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Union Falls Trail

HARD 75 reviews
#33 of 228 trails in

Union Falls Trail is a 15.4 mile heavily trafficked out and back trail located near Yellowstone National Park, Wyoming that features a waterfall and is rated as difficult. The trail offers a number of activity options and is best used from May until September. Horses are also able to use this trail.

Distance: 15.4 miles Elevation Gain: 1,938 feet Route Type: Out & Back

backpacking

camping

hiking

horseback riding

running

forest

river

views

waterfall

no dogs

Union Falls is the second highest waterfall in Yellowstone, towering above at 260 feet. The falls is very unique in shape and serves those bringing cameras very well. Union Falls is located in the southwest section of Yellowstone. Formed as two creeks come together and fall over 250 feet. Union Falls is very impressive and worth the hike to get to.

hiking
1 month ago

Honestly, the trail itself is quite lackluster, just pines and the occasional creek. There is a creek you have to cross about a mile and a half in that, at least the day I did it, will reach up to your knees at a point, but is mostly ankle to calf deep. Despite the actual hike however, the waterfall at the end is worth it. One of the most beautiful I've ever seen in my life, incredibly unique, and rather solitary so no worries of overcrowding, I was the only one there. So if you're looking for a challenging or interesting hike, this isn't the one for you, but I would recommend it for the waterfall alone.

hiking
1 month ago

Amazing! The trail had some flats and ups and downs both ways, but on the way back there was about a mile uphill, but not too strenuous. The waterfall was beautiful, and the slightly warm springs were fun. It was a cooler day and there were hardly any bugs this time!

hiking
2 months ago

I would highly recommend this trail!! Beauty in all directions! Amazing things to find! So worth the time and miles! Pictures do not do the waterfall justice and the hot springs are so worth it!!!

hiking
bugs
2 months ago

hiking
2 months ago

trail was wonderful took my 4 boys and girlfriend on it horse flies were bad and mosquitos but the falls was well worth it was blissful didnt go to scout pool . camped overnight gotta love yellowstone weather luckily got tents up before rain and hail.

hiking
2 months ago

Very beautiful trail. 16 miles round trip. There is a 20-30 foot river a mile from parking. The river is fairly easy to pass. Didn’t see any bears:( the way back out is a little harder than into Waterfall. At the bottom is a very nice breeze! The hike fairly moderate but long. The only access to water is from rivers.

hiking
bridge out
bugs
2 months ago

This is a truly magical trail! You begin by hiking into Yellowstone National Park and have many adventures ahead of you from there. You have to wade across some moving water about a half a mile from the beginning (and thus also the end) of the hike. The waterfall is really sweet and it is possible to traverse down to it off trail, though it’s pretty steep and very slippery. Go the extra mile or so at the little fork to go to the warm (not hot) spring and chill. There are many horse flies and mosquitoes throughout so bring your bug spray! It’s not too heavily trafficked but it seems like a popular Boy Scout route.

hiking
2 months ago

mosquitos were not fun. next time I'm doing it in late August or sep

hiking
bugs
2 months ago

This was a difficult hike especially on the way out. This was only my second hike and I’m outta shape; just to put it in perspective. It’s about 9 miles to view the gigantic beautiful waterfall! Some of the group I hiked with went off trail, steep, slippery terrain down to the waterfall. On the way back we turned off onto the trail that led to the hot spring. This was the best part by far!! Temp was perfect for the hot day that it was! Able to jump off rocks. Mosquitos were thick all day and horse flies swarmed the hot spring. Still worth it though. Nine mile hike out felt like it was 99% up hill.

hiking
3 months ago

Nice hike with an incredible falls at the end. the trailhead has a pretty long and sometimes bumpy road but it is worth it. Only have to ford one river without a log and it wasn't bad. Very nice area.

hiking
5 months ago

Great hike I’m a camp loller right next to this hike and have done it many times, the view is most bodacious. Just watch out for cardiac hill.

5 months ago

Wicked hike!

7 months ago

love that trail! many boyscouts use this trail some days alot of people hiking. guess that goes with beautiful places many wild flowers and a perfect place to ride horses!

hiking
7 months ago

Loved this hike!!! We did this hike in late August (absolutely no bugs). It’s long but worth every single step. Plan for water crossings. Also, I think the trail is longer than 15 miles. Our GPS had us well over 19 miles. We highly recommend this hike.

Sunday, October 14, 2018

One of my all time favorite hikes! Make sure to plan accordingly for river crossings, you’ll want to be able to take of long layers/have shorts for wading. Water shoes are a must! Scout hole provides a perfect resting place before venturing back out.

Thursday, August 30, 2018

I’ve done the hike 7 times and it’s been worth it every time. Swimming in ouza pools is a party too!

hiking
Tuesday, July 24, 2018

Fording Rivers Unique

Friday, July 20, 2018

This trail is more moderate than difficult. However, the distance is tiring. I would say it is harder to hike back out than it is to hike into the falls. It took my fiancé and I about 3 hours to get to the falls and 4 hours to get out. This trail is absolutely stunning. It is well worth the distance. Getting to the trail is kind of tricky. It will feel like you’ve been driving forever, but just keep going. As soon as you get to Grassy Lake Reservoir Dam, the road to the trail head is at the bottom by the spillway. The trailhead is not posted at the beginning. It’s on the right hand side after you crossover the spillway(walking). If you do not have four wheel drive I would recommend parking at the dam and walking down the road. It’s not that far. Don’t forget some water shoes or sandals! You will be crossing a river. Also bring LOTS of water. YOU WILL NEED BUG SPRAY. We used an entire can of spray on this hike. The bugs are thick. We ate lunch at the falls and it was definitely a memorable time. ✌️

hiking
Wednesday, July 11, 2018

Hello my fellow camp Lollers ;) me as well decided to 5 star my most favorite bodacious hike :) can't wait to do it again this summer

backpacking
Tuesday, June 05, 2018

Quite possibly one of the best destinations in the park. Takes a bit of effort to get to the trailhead, but definitely worth it. I think it's best done as an over night hike so you have more time to enjoy the falls and relaxing in the nearby Ouzel/Scout Pool. The river crossings are typically much too high in the spring, usually the hike isn't really accessable until mid July at the earliest. And just as everyone else has said, you need bug spray!

camping
Thursday, February 22, 2018

Well worth the hike will do again

backpacking
Tuesday, October 03, 2017

great trail.... away from all of the people in YNP... bring deet if hiking in summer.. tons of mosquitoes and flies.. a little difficult when hitchhiking to the trailhead... I hitched from old faithful to the start of the dirt road... then off and on until I got to the trailhead... I think I spent more time hitchhiking to the trailhead than on the trail! haha .. fun trail.. wide river ford at the beginning..

hiking
Tuesday, September 26, 2017

I have always come in from Fish Lake. This trail features three river crossings, which for me adds to the fun, and skips the elevation gain of the Grassy Lake trail. About the same total distance. Hardly ever meet anyone on this trail.

hiking
Monday, September 04, 2017

Great hike, came back in the dark, couple creek crossings, one big one . The water at Ouzel Pool was amazing. Heading back before the season ends. Falls was beautiful, the pool was the best.

Sunday, September 03, 2017

The scenery is worth every step. We started at Cascade trail instead of Grassy Lake and did the Terrace Falls trail then came back to the trail sign and headed up Union Falls. Terrace Falls followed the river so the scenery was completely different than Union Falls. This made it a total of about 19.5 miles. Bring a swim suit and plan on swimming in the warm spring just a .3 mile detour to the left before Union Falls. At Unions Falls there is a trail that will take you down to the falls so you can get right next to it. Worth every step. 1 major river crossing. Heading back the cold water felt AMAZING on sore muscles. Even though this is not a steep trail plan on it taking you twice as long to get back because it is so long.

hiking
Wednesday, August 30, 2017

I would rate this trail moderate, not hard as in the description. Coming from the Ashton side, there's about 25 miles on dirt roads, and it will take some time to get there. About one mile in, you will need to ford the Fall River. Depending on the time of year, the river can be anywhere from knee deep to thigh deep. As far as water crossings go, this one isn't bad at all. Trekking poles help a lot. Beyond that, the trail is pretty straightforward, kind of rolling up and down the hills. There's generally plenty of shade, and plenty of spots to filter water. The falls, located about 7.5 miles from the trailhead, are worth the effort. This is the second largest waterfall in Yellowstone, and is named for the two streams that converge at the waterfall. Expect mosquitoes and horseflies from late June through early September (bring plenty of bug spray). Bear spray is also recommended.

Wednesday, August 23, 2017

Awesome! The hike back is harder than the hike in. Easily one of my favorite hikes!

Tuesday, September 20, 2016

Just an FYI... the road to this trailhead is now closed for the season :)

hiking
Friday, September 09, 2016

This hike is awesome! We did it in early September and the water was low and there were NO bugs. Going to scout pool is a must. It took us about 3 hours each way. Definitely worth the hike

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