Mount Marcy is the largest of 46 High Peaks, tallest mountain in the Adirondacks and highest point in New York. Nearby Lake Placid is a hugely popular mountain resort town and hiking Mount Marcy is our top recommendation for best things to do in Lake Placid.
There are four major trails you can climb to summit Mt Marcy, but in this guide we will walk you through the shortest and most popular including the Adirondack Loj parking lot and Van Hoevenberg trailhead.
In our detailed Mount Marcy guide, we will also show you:
- How to properly prepare for hiking Mt Marcy
- Important parking information
- A detailed walkthrough of the Mount Marcy hike
- Where to stay when hiking Mount Marcy
- Things to pack for your long hike
- Tips for hiking mount marcy in a day
Let’s get right into planning your Mount Marcy hike in New York’s spectacular Adirondack Mountains!
Our Mount Marcy Experience
We hiked Mount Marcy in October 2020 and included this bucket list NY hike as part of a larger New England road trip.
While we had many other hikes on our agenda for this trip, Mount Marcy was certainly the one we were the most excited for because it is the highest mountain in New York.
Having road tripped around the US for several years now, we think Mount Marcy is one of the most iconic hikes on the east coast and have included it in our guide featuring the best hiking trails in the United States.
What Is Mount Marcy?
The summit of Mount Marcy is the highest point in New York and commander in chief of the spectacular Adirondack High Peaks.
In Mohawk, the mountain is known as “cloud-splitter’ but it was renamed Mount Marcy after a 19th century governor of New York who gave the go ahead to survey the Adirondack region.
Most of the 15 mile round trip trail is inside forest, following Phelps Brook and Marcy Brook, before opening up above the tree line for a final steep climb to the summit.
A cone shaped summit is flat enough to accommodate dozens of hikers at the same time and in summer you will share the peak and stunning views with plenty of others.
Mount Marcy is a full day hike, starting very early and ending in the late afternoon. Let’s take a look at preparing thoroughly for your hike.
Interesting Fact: Teddy Roosevelt was at the top of Mount Marcy when he had to descend and head for Buffalo to be sworn in as president in 1901.
Mount Marcy – New York’s Tallest Peak Factfile
- Hike Distance: 14.8 miles roundtrip
- Hiking Time: 7-11 hours
- Elevation Gain: 3,166 ft (965m)
- Summit Height: 5,344 ft
- Trailhead: Van Hoevenberg
- Parking Fee: US$ 15 per vehicle
- Dogs Allowed: Yes, Mount Marcy is dog friendly
How Long Does It Take To Climb Mount Marcy?
According to AllTrails, Mount Marcy is an challenging route that takes an average hike time of 8 hours and 25 minutes to complete.
Keep in mind this average time will not include any breaks, time enjoying the summit or stops for photographs.
When we hiked Mount Marcy, our combined smartwatch tally clocked in at an average of 31,434 steps, which means this is no easy hike.
Technically, only the last mile is challenging with exposed and steep rock faces to ascend. However, the length and total time of the Mt Marcy hike does give this trail a strenuous rating.
Preparing To Hike Mount Marcy
Preparing properly for hiking up Mount Marcy comes down to making sure you have the right gear as well as enough food and water for the season you are climbing the mountain.
The 15 mile round trip hike will take you anywhere between 7-11 hours, depending on how quickly you hike and how long you spend admiring the views.
Here are a few Mount Marcy hiking tips to consider before you climb up New York tallest mountain:
- Check a detailed weather report for Mount Marcy the day before but be prepared for changeable conditions. The summit is extremely exposed and wind gusts can be strong.
- Weather conditions will play a huge role in what you need to wear and carry in your day pack, which we will cover later in this guide.
- Remember, this is not a technical hike, but it is a long one and most of the trail is uneven underfoot. Be sure to choose the right footwear (also discussed later in this guide).
- Pack layers even on a warm day because weather on Mount Marcy is changeable and it’s cold at the summit.
- Eat a hearty meal and get completely packed up the night before. An early night is recommended because you will have to get up excruciatingly early in order to get a parking spot.
Use A Popular Hiking App
We recommend you study the trail for Mount Marcy prior to your visit and use a hiking app to navigate the trail for your entire hike.
Download an offline trail map of the Mount Marcy hike using your preferred hiking app. We always use GAIA GPS to track our progress and record our hiking statistics.
>> Receive 20% off a GAIA GPS subscription here
After hiking hundreds of miles, GAIA GPS is always our top recommendation when it comes to hiking apps because it offers very accurate GPS navigation and trail information.
You can also check out the comments on AllTrails to see what hikers have recently said about the Mount Marcy trail.
Need a new hiking app? Don’t miss our round up of the best apps for hiking trails meant for both beginners or seasoned hikers.
The Mount Marcy Parking Problem
Hiking Mount Marcy is going to be a long day, so you will naturally need to get an early start from your hotel in Lake Placid or nearby.
It is better to start earlier than necessary because walking in the dark is easier when you are fresh and more alert. The alternative is finishing later in the darkness when you’re exhausted and that is when accidents happen.
The main problem stems from the limited amount of parking spaces available in the Adirondack Loj parking lot. To make matters worse, the whole parking situation is a taboo topic if you read about it online.
What Time Do You Need To Arrive To Get A Parking Spot?
When planning our own hike, getting parked was our major concern. What time would we have to arrive in order to guarantee a parking spot? And what do we do if there are no spaces left?
We arrived at the Adirondack Loj parking lot at 5:25 am at the beginning of October. The car park was approximately 70% full.
By the time we had paid to park, grabbed our gear and signed in at 5.45am, the parking lot was at about 90% capacity. We imagine by 6:00 am it would have been completely full.
Aiming for a 5:30 am arrival time should secure you a space in most seasons, but if we were to hike Mount Marcy again tomorrow, we would try to arrive around 5:00 am as this trail has become increasingly popular.
Unfortunately, due to the furore around getting parked, hikers are arriving earlier and earlier just to guarantee a spot. If you are hiking in peak season during summer, you may want to consider an even earlier time.
If you don’t get a space in the Adirondack Loj parking lot, you will have to park at South Meadow Trailhead, 1 mile back up the road you drove down. Therefore, you would be looking at an additional 2 miles total hiking distance.
Hiking Tip: Keep in mind the Adirondack Loj parking lot is also the trailhead for several other hikes in the area so you will be competing for a spot with many other hikers. Arrive early and save yourself a headache!
Directions From Lake Placid To Mount Marcy Hike Trailhead
Mount Marcy hiking trailhead begins in the Adirondack Loj parking lot near Heart Lake. To reach the parking lot you need to take Adirondack Loj Road off NY-73 (Cascade Road).
The majority of hikers will set up base in Lake Placid. From Mirror Lake in town, head South and take the right onto Sentinel Road and follow this until you turn right onto Adirondack Loj.
It is an easy route, so no need to worry about getting lost in the morning.
- Distance from Lake Placid: 8 miles
- Drive time from Lake Placid: 15-20 minutes
Mt Marcy Hike Walkthrough
With preparation and parking out of the way, now let’s get onto the fun part!
We will walk you through hiking Mount Marcy with plenty of images so you can visualize the trail and what you’re up against.
1. Parking And Signing In For Mount Marcy
We arrived around 5:30 am to guarantee a parking spot in the dirt track parking lot. There are no designated lined spaces so please try to park respectfully and take up minimal room with your vehicle.
Entry to the Adirondack Loj parking lot is US$ 15. You will either pay a person inside a kiosk or put an envelope into a mail slot if you arrive before a person is in the kiosk.
You are still required to pay US$ 15 if the kiosk is unmanned. Post a form filled in with your license plate information and cash inside an envelope through a mail slot at the kiosk. Try to bring exact change if possible.
Once you have paid and parked, walk through the parking lot, away from the kiosk and bathrooms toward Van Hoevenberg trailhead. You will sign a register with names of all hikers in case of emergency.
Hiking Tip: You will need a pen at hand in order to write your details down on the envelope. There was no pen to use when we signed in so we were happy to have brought one with us.
2. Forest Trail In Darkness
By the time you set off on your hike at around 5:45 am, the sky might be brightening in summer but in early spring and late fall it is likely to be pitch black when you hit the trail.
No matter what time of year you hike, don’t forget your head torch just in case.
You can check Lake Placid sunrise times here.
The first part of the trail is flat, easy and beautiful. You will walk through dense forest, across wooden bridges and narrow boardwalks. It has a serious Narnia vibe and it’s extremely peaceful.
In fall, the foliage was amazing.
When we returned later in the day and saw how gorgeous the pink, red, orange and yellow leaves were through this section, we were disappointed we hiked in total darkness in the morning.
Be aware of slippery leaves and exposed tree roots along these forested sections of the trail.
3. Mount Marcy Dam
The first real landmark you reach is Marcy Dam at 2.1 miles into the hike. In truth, there’s not much to see here but it should now be starting to brighten up, even in spring and fall months.
But the good news is the Mount Marcy Dam marks the beginning of a slow and gradual climb.
Follow signposts to Mt Marcy and cross the wooden bridge to a notice board, which will display any current warnings or closures. Be sure to pay attention to this sign!
When we hiked, this sign included information about a section of bridge that was closed further along the trail. Since we read this sign, we knew to continue and cross at a later point.
Once you begin to notice a gradual incline as you walk along uneven rocks, settle into a nice and easy but efficient cadence. This is a long, slow and steady incline for quite some time.
4. Indian Falls Waterfall Stop
After what feels like forever carefully watching every foot placement in between small boulders, you will finally reach Indian Falls. This is the perfect place to take your first real break of the hike to Mt Marcy summit.
Follow the flow of water until you reach the point in which it cascades over smooth rocks and take in stunning views of rolling hills as far as the eye can see.
Fuel up with food and water before heading back into the forest and taking on the next phase of your ascent.
5. Fun Rock Climb To The Summit
Not long after re-entering the forest at Indian Falls, you will burst out of the tree line and the trail becomes far more exciting. Follow yellow painted markers to stay on trail.
Uneven boulders with footsteps forged into them, long wooden boards crossing swampy grassland and steep inclines will keep you on your toes.
By now, you are out in the open, exposed to the elements and in the hands of the weather gods.
Even on a sunny, warm and calm day, it is likely to be windy up here. A more likely scenario is strong wind and horizontal rain battering you as you navigate the steeper sections of the climb.
When we hiked in October, large sections of boulders on the main trail approaching the top were covered in thin layers of sheet ice.
This is the time to slow down and carefully consider your approach to the summit.
Safety aside, this is the most fun and interesting section on the Mount Marcy hiking trail. There are sections of fragile Alpine vegetation which must be avoided for preservation.
6. Take In Spectacular Summit Views
You can see Mt Marcy summit from afar, which means you know your target and can set your mind to the goal.
Once you arrive at the summit, you will be met by a park ranger who will tell you to stay clear of cordoned off sections of vegetation and answer any questions you might have.
A little further along the flat summit you will find plaques dedicated to the history of Mt Marcy, with some large boulders as the official top of the ascent.
Congratulations because you have officially climbed the tallest mountain peak in the state of New York!
Enjoy your achievement and the truly awesome 360 degree views stretching into Canada, Vermont’s Green Mountains and the Adirondack High Peaks.
If you hike on a clear day, your views will be much better than our grey, overcast, dull and misty views.
Weather permitting, it’s time for lunch. We couldn’t eat at the summit, it was too windy and cold, so instead we dropped down the steep section and took shelter behind a huge boulder.
7. Descend The Same Way Via Van Hoevenberg Trail
It’s important to enjoy the summit because now you have to come to terms with the fact you have a 3-4 hour descent to contend with.
Quick and experienced hikers can be back at the parking lot in a few hours but for most it will be a long and at times arduous descent.
Be sure to take regular breaks by topping up with water and food when necessary.
It is important to watch your footing on the way down, slippery leaves and rocks are common along the trail.
The difficult part is keeping your concentration 8, 9 or 10 hours in because it only takes one misplaced footstep to fall and have an accident.
Unfortunately, the section you walked in darkness between Marcy Dam and the car park will feel much longer on the way back, but at least this time you can enjoy the scenery in daylight.
Once you are back at the parking lot, it is time for a shower, a nice meal out and a celebratory beer!
Want to see more Mount Marcy photos? Don’t miss our photography guide to summiting New York’s highest peak.
Best Time To Hike Mount Marcy
Mount Marcy will be a beautiful hike anytime of year, but there are certainly advantages to disadvantages to certain seasons.
Shoulder seasons are always a good time to visit US national parks or hike popular trails in beautiful places like the Adirondacks.
Spring And Fall
Hiking Mount Marcy in the spring and fall means crowds will be much thinner compared to summer, not only on the trails but also in accommodation around the region.
The spring season will bring higher levels of water due to the snow melt, but you will be rewarded with beautiful flowers blooming. However, if snow remains on the mountain for longer in the year, it may be difficult to hike.
In our opinion, autumn is the perfect time to hike Mt Marcy because this time of year offers beautifully vibrant fall foliage, perfect hiking temperatures and you don’t have to worry about the snow as much.
Keep in mind the fall season can be quite busy during the 7-14 days of the peak fall season at the beginning of October. This time of year will be an expensive time to visit Lake Placid and hike Mount Marcy.
If you are hiking from mid-October to the end of October, it is not uncommon to experience snow especially at the summit. Always check weather conditions prior to hiking Mount Marcy.
Summer
Earlier sunrise and later sunset means you have more time to hike in daylight, warmer conditions and a higher chance of a clear summit.
However, summer brings swarms of crowds to the trail and local areas. Hotels are more expensive and it may be difficult to find availability as accommodation is in high demand.
Winter
Harsh upstate New York Winter brings a different world to the Adirondacks.
If you want to hike Mount Marcy in winter, you will need serious clothing and equipment to brave the elements such as microspikes, extra layers of clothes, goggles and heavy duty survival gear.
Only experienced hikers should attempt hiking Mount Marcy in winter.
Where To Stay When Hiking Mount Marcy
Most people visiting the region and hiking Mt Marcy will stay in nearby Lake Placid.
Lake Placid is perfectly located as a base for the best things to do in the area and is just 15-20 minutes drive from Adirondack Loj parking lot.
However, there are other small nearby towns and accommodation options to consider if you are visiting just to hike this famous trail.
You can read our complete guide to the best hotels in Lake Placid NY on our sister site Best Hotels Anywhere or take a look at any of the top rated options below:
- Cobble Mountain Lodge: Best for larger groups
- Golden Arrow: Luxurious option on Mirror Lake
- The Haus: Apartment on Mirror Lake
- Town House Lodge: Best for those on a budget
Alternative Hike: If you’re looking for a shorter and easier hike in the area, try family friendly High Falls Gorge on the way to Whiteface Mountain.
Where Did We Stay When Hiking Mount Marcy?
If you’re looking for somewhere special to stay in the Adirondacks, book a room at Snow Goose Bed and Breakfast.
The quaint B&B is located in Keene Valley, which is 22 miles (32 minutes drive) from Adirondack Loj parking lot and the Mount Marcy hike.
So, you would either have to get up and set off 15 minutes earlier on the morning of your hike, or do what we did:
- Check out of your Lake Placid hotel in the morning
- Hike Mount Marcy
- Check into Snow Goose to unwind after a long day of hiking
The owners of the Snow Goose are great and we enjoyed a delicious homemade breakfast in the morning surrounded by a peaceful setting.
The B&B is also located very close to Indian Head, an immensely popular photography location. Next time we’re in the Adirondacks, we’ll be staying here again!
Where To Camp When Hiking Mount Marcy?
If you need a place to camp the night before or after hiking Mt Marcy, the most popular place to camp when climbing Mount Marcy is Marcy Dam.
You can not camp on any of the summits in the Adirondack Mountain range and primitive camping is only permitted up to 3500 ft in elevation, so this is why the Marcy Dam is a great choice for camping.
Camping at Marcy Dam is popular because this site is located on the shortest trail up Mount Marcy, the Van Hoevenberg Trail, and you can reach Algonquin (another high peak) in less than 5 miles.
Need a campsite near Mt Marcy? Take advantage of our exclusive 30 day free trial of The Dyrt PRO to get reservations at sold out campgrounds with $0 booking fees and gain access to free dispersed camping locations around Mount Marcy or Lake Placid. You can try PRO for free, no strings attached!
What To Pack For Hiking Mount Marcy
Now that you know what to expect when hiking Mount Marcy and where to stay, we want to show you what to pack for this long grueling day hike.
What you pack for the trail will depend entirely on weather and season, but for the average hiker in average conditions, we suggest you pack the following:
Food For The Trail
Do not underestimate how much food you will need because the more energy you expend, the more hungry you will become. No one wants to run out of food on the hike, but you also don’t want to bring too much.
For our Mount Marcy hike, we each brought:
- One basic ham and cheese sandwich
- A few energy bars
- Trail mix
- Some jerky
- A bag of gummies
- One Gatorade
We ate our sandwiches at the summit and snacked at different points throughout the entire hike. It was only just about enough and we were hungry at the end, but we had no extra weight to carry.
Water And Drinks
Proper hydration is just as important as nutrition during your hike. As a general rule of thumb, the average human being needs to drink about 2.0L of water per day.
However, this number doesn’t take into account strenuous exercise such as climbing Mount Marcy so you should be consuming even more water than this average amount.
Your water requirements for Mount Marcy will depend on weather conditions (warmer weather means more water), but you should aim to drink about 3.5L per person including electrolyte drinks.
Personally, we always try to have at least 1.0 L of water on us at all time just incase. We both drank about 3.0 L during our hike. We also had more water and electrolyte replenishments when we got back to the car.
You can top up your water bottle at Indian Falls, but be sure to use a filtering device. We also like to carry a LifeStraw for emergencies.
Hiking Tip: Be sure to prehydrate and eat well in the day leading up to your hike so you give your body the best start possible.
Footwear And Socks
The hike up Mount Marcy will involve many different terrains. You want to wear a sturdy hiking boot or trail running shoe. If you hike in the winter, you might even want to consider snow shoes and microspikes.
Kristen hiked Mount Marcy in these Columbia Newton Ridge Boots and Mark wore these Adidas Terrex Free Hikers.
Socks are another extremely important consideration for your hike because the wrong ones will give you blisters or make you uncomfortable leading to a terrible time on the trails.
But we have an amazing tried and tested sock recommendation for you!
After hiking hundreds of miles the past few years including Rim to River in the Grand Canyon, the Enchantments in Washington and traversing Mount Blanc in Europe, there is only one sock for the job.
Darn Tough hiking socks!
>> Shop Darn Tough: Amazon | REI | Darn Tough
Having used this company for years now, our feet always stay dry and we have yet to experience even one blister.
The Right Hiking Layers
We hiked Mount Marcy in October with the following layers:
- One pair of pants or leggings
- Two pairs of Darn Tough socks
- Short sleeve base layer
- Thin long sleeve mid layer
- Thick fleece layer
- Thin waterproof jacket
- Hat + gloves (for the summit)
Depending on the time of year you hike Mount Marcy, you may have to adjust your required layers for the weather.
Hiking Backpack
Take a comfortable and breathable day pack for you hike.
We used our Peak Design Everyday backpacks to protect our camera gear while hiking. If you do have not camera gear, you should check out the Osprey Skarab (men) or Osprey Skimmer (women).
Bring A Headlamp
No matter the time of year you plan your Mount Marcy hike, you should always carry a headtorch. If something happens and you have to spend an unplanned night on the trails, you have to be prepared.
Unless you are hiking in summer, the beginning as well as end of your hike might be in total darkness. Do not solely rely on your smartphone light, you should be wearing a quality head torch.
>> Buy Black Diamond Headlamp: Amazon | REI | Black Diamond
Want to see more hiking gear? Don’t miss our guide featuring the best things to bring a day hike or use our popular gift guide for hikers to find the perfect present.
Mount Marcy FAQ’s
Let’s take a quick look at some of the most frequently asked questions about hiking Mount Marcy.
Mount Marcy is a long slow and grueling trail, but the hike is worth it for spectacular far reaching views over the Adirondack Mountains from the highest point in New York.
Yes, the Adirondacks are home to black bears who are omnivores eating berries, nuts, fruits, corns, seeds, honey, etc. There are no grizzly bears in the Adirondack Mountains.
The most popular and easiest trail to summit Mount Marcy is the Van Hoevenberg Trail starting in the Adirondack Loj parking area. You can combine your hike up Mount Marcy with many of the other nearby peaks or use other longer trails to summit New York’s highest mountain.
Our Popular New York State Guides
- Lake Placid – Fun things to do in Lake Placid, New York
- Photography – Summiting Mount Marcy in photos
- High Falls Gorge – How to hike High Falls Gorge near Lake Placid
- Eternal Flame Falls – Where to find Eternal Flame Falls in upstate NY
- Waterfalls – Complete guide to finding the best waterfalls in NY
NY Finger Lakes Guides
- Finger Lakes – Best things to do in the NY Finger Lakes
- Watkins Glen – Guide to hiking Watkins Glen Gorge Trail to Rainbow Falls
- Village of Watkins Glen – Things to do in the Village of Watkins Glen
- Letchworth – Everything you need to know about Letchworth State Park
- Taughannock Falls – Complete guide to Taughannock Falls Overlook
- Robert H Treman – How to hike Robert H. Treman Gorge to Lucifer Falls
- Buttermilk Falls – Complete guide to visiting Buttermilk Falls State Park
- Stony Brook – Adventurous things to do in Stony Brook State Park
- Finger Lakes Waterfalls – Where to find amazing Finger Lakes waterfalls
Want more New York content? Head over to our New York Travel Guides to explore the Finger Lakes, Adirondacks and the best of NYC.
We hope this guide to hiking Mt Marcy helped with your summit up the highest mountain in New York State.
Please let us know if you have questions about climbing Mt Marcy or hiking in the Adirondacks High Peaks region.
Happy Hiking,
Mark and Kristen
Enjoy This Mount Marcy Hiking Guide? Pin It For Your Visit!
Note: This article contains affiliate links. When you make a purchase using one of these affiliate links, we may earn a small commission at no extra cost to you.
All Rights Reserved © Where Are Those Morgans, LLC. Republishing this article and/or any of its contents (text, photography, maps, graphics, etc.) in whole or in part is strictly prohibited.
Mark and Kristen Morgan are travel, hiking and photography experts. Over the last 6 years traveling full time, they have explored more than 40 countries and 30 US states.
Where Are Those Morgans has been featured in USA Today, Gestalten, Get Your Guide, CityPASS and Condé Nast Traveler along with various other publications. Read more about us.
Merc
Thursday 30th of June 2022
What day of the week did you hike on? Also, if parking runs out, does the other parking lot fill up fast as well?
Mark and Kristen Morgan
Friday 1st of July 2022
Hi Merc, we hiked Mt Marcy on a Sunday in early October and arrived very early because it was a weekend during fall foliage season. If you hike midweek you'll have a better chance getting a space in the main lot even a little later in the morning. Definitely avoid holidays or long weekends. Our advice would be try to get there early no matter when you visit, just so you don't have to park in the South Meadow trail lot. It would add on 1 mile and 20 minutes to each side of your already long day up to Marcy summit. Have a great hike!
John
Sunday 1st of May 2022
Can you spend the night on the mountain and leave your car at the Adirondack Loj for 2 days?
Mark and Kristen Morgan
Monday 2nd of May 2022
Hi John, we're not entirely sure but we don't think what you have in mind is 'permitted'. There are park rangers at the parking lot and it is monitored but you may be able to pay up front for 2 days. We know you are not allowed to camp above 3,500 ft (which includes most of Mt Marcy) but you could technically camp at Marcy Dam which is below that threshold. Sunrise photography from the summit would be awesome, so maybe start hiking later in the day and summiting an hour or so before sunrise? Best of luck!
michael
Tuesday 15th of February 2022
excellent coverage of the trail both pros and cons, only comment is the the lack info on either on poison ivy, ticks and poison reptiles(snakes). can you comment, will be making a spring hike on Mount Marcy. thank you sarah and mike
kevin
Monday 16th of May 2022
@Mark and Kristen Morgan, The Timber Rattlers/Copperheads end in the Lake George region (aka Tongue Mtn.). They're not up in the High Peaks though you'll likely see garter snakes or the like. Ticks generally end at a certain elevation and permethrin on clothing is the only thing I know of that works for certain (I've had lyme, so I strive to not repeat that). I'm sure ticks will find higher elevation homes as the climate changes since they weren't in the ADKs a decade ago as they are now. As of a year or so ago, they've yet to be seen at elevations above JBL for instance. ...my house in the Jay area at 1200' has plenty, however. Never seen poison ivy in the Marcy area either though it's all over in some areas, again at lower elevations (the Ausable has groves). It's bright red in fall so you'd have noticed. Happy hiking.
Mark and Kristen Morgan
Friday 18th of February 2022
Hi Sarah and Mike, thanks for getting in touch and it's great to know you'll be hiking Mt Marcy. Ticks are common in the Adirondacks from April through September so depending on when you hike, you could just about catch the beginning of tick season. Poison Ivy is also found in the area, but in Spring it might be yellow rather than green so be aware of both colors. We didn't see or have issues with either during our hike in Fall. Wearing long pants and sticking to the trails should be enough of a deterrent for both. There are poisonous snakes, including the Timber Rattlesnake but we've never heard of anyone seeing any on the Mt Marcy hike. Check the recent comments on AllTrails in the weeks leading up to your hike to see if anyone mentions poison ivy, ticks or snakes. Have a great hike!