Hiking Project Logo

Fish Lake-Mountain Ash Cutoff Trail

Intermediate

Trail

1.9 mile 3.1 kilometer point to point
Intermediate

Elevation

Ascent: 56' 17 m
Descent: -62' -19 m
High: 6,490' 1,978 m
Low: 6,447' 1,965 m

Grade

Avg Grade: 1% (1°)
Max Grade: 3% (2°)

Dogs

No Dogs
Driving directions Take a virtual tour
Zoom in to see details
Map Key

Trail shared by Tom Carter

A cutoff trail most often used in route to spectacular, 250-foot Union Falls.

Tom Carter

Features River/Creek

The Falls River ford at the beginning of this trail, and the Mountain Ash Creek ford at the end are both difficult. They should not be attempted before mid-July, after the spring runoff subsides and the river drops down to no more than mid-thigh deep.

Description

Most hikers (and horse parties) using this trail are headed to spectacular 250-foot Union Falls. But beware, the trailhead is one of the most difficult to reach in the Yellowstone trail system. Moreover, the two river fords should not be attempted before mid-July. Start southwest of Fish Lake, which is reached by a 1.5 mile high-clearance vehicle spur road on the north side of the Flagg-Ashton NFS Road (also called the Grassy Lake Road) about 18 gravel-road miles west of Flagg Ranch. First take the 1.2 mile Fish Lake-Mountain Ash Spur Trail which leads to our trail, the Fish Lake-Mountain Ash Cutoff Trail.

From the parking area southwest of Fish Lake, follow the Fish Lake-Mountain Ash Spur Trail 1.2 miles north to a trail junction, just inside Yellowstone NP. A trail to campsite 9C6 lies to the right. Turn left and continue another .2 miles to the next junction where the Mountain Ash Cutoff Trail splits off to the right and begins its 1.9 mile course to join the Mountain Ash Creek Trail.

The Cutoff Trail immediately fords the Falls River. Its a tricky, knee-to-thigh-deep ford even after the spring runoff subsides, usually by mid-July. Once across the river, the trail travels over rolling terrain and crosses knee-to-thigh-deep Mountain Ash Creek before joining the Mountain Ash Creek Trail.

From here, to the right, Union Falls lies just 5 miles away.

Thanks to guidebook author, Tom Carter, for sharing this trail description. To learn more about visiting Yellowstone, check out his book, Day Hiking Yellowstone.

Hiked this trail?

We need help with the following missing trail information:

Family Friendly, ADA Accessible, Need to Know, Flora & Fauna

Contacts

Rate This Trail

Rate Quality


   Clear Rating

Rate Difficulty

Share This Trail

Check In

Check-Ins

none

Stewarded By


Trail Ratings

  2.0 from 1 vote

#32898

Overall
  2.0 from 1 vote
5 Star
0%
4 Star
0%
3 Star
0%
2 Star
100%
1 Star
0%
Trail Rankings

#715

in Wyoming

#32,898

Overall
2 Views Last Month
224 Since Sep 9, 2015
Intermediate

0%
0%
100%
0%
0%
0%

Photos

Mountain Ash Creek Trail.
Sep 9, 2015 near Yellows…, WY

0 Comments

Hiking Project is part of the REI Co-op family,
where a life outdoors is a life well lived.

Shop REI Hiking