Mount Marvine and Mount Terrill via Black Flat in Fishlake National Forest, UT

Hike Mount Marvine and Mount Terrill via Black Flat Fishlake National Forest, UT

Class 3 13.8 miles 3900 gain 6-8 hrs Loop Sep 27, 2019
Effort
Beauty
Personality
Solitude

Mount Marvine and Mount Terrill via Black Flat GPX Track

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After spending a few days in this area doing Fish Lake Hightop and Hilgard Mountain, I returned to check out Mt. Marvine and Mt. Terrill to feel like I really got a sense of the Fish Lake region. These are a pair of of peaks that jut out from the rolling meadow-filled landscape. Mt. Marvine requires a scramble to its rocky summit, while Mt. Terrill is a long and mellow slope to the top of a plateau. The route I took to approach both peaks comes from the east along the Black Flat Trail. I wanted to make this a longer day to see some of the tarns visible on a map, as well as enjoy the fall aspens changing colors. My route can be shortened significantly if you drive in from the west to 38.6823165,-111.6357956, but I can't speak for the road conditions coming from this way.

I didn't realize it, but the "Black Flat Trail" is an ATV route, not a singletrack trail. Normally I steer clear of these because I prefer hiking trails to dirt roads, but I already made it to the trailhead and decided to just carry on. It seems like the Black Flat Trail actually got a bit of a re-route somewhat recently, as the roads are marked differently on Google Maps. I started out hiking along a closed section of ATV trail, following a deteriorated doubletrack around some pretty tarns and converged to the maintained ATV road. I don't know if my route or this ATV road is considered the Black Flat Trail, but whatever, I liked the way I went. I followed this ATV road the entire way to the UM Pass (the pass separating Mt. Marvine and Mt. Terrill).

From the UM Pass, I headed south to Mt. Marvine first, following its northern ridge through some light bushwhacking before reaching a fairly large boulder field at Mt. Marvine's eastern base. I boulder-hopped until I passed the southernmost section of Mt. Marvine's well-fortified summit cliffs. I located a reasonable-looking Class 2+ route up the boulders, leading to the southern side of the cliffs. Maybe there's a more reasonable way up, but I found myself a little stressed out on very loose scree on the steep slope. For this reason, I'd call this section Class 3, even though there are no climbing moves. Finally on the ridge, I worked around the west side of Mt. Marvine until I got to the northernmost side of the cliffs, where a short Class 3 move led to the summit. Basically, the route I chose required me to wrap around the entirety of Mt. Marvine.

Back at UM Pass after coming back from Mt. Marvine, I started north toward Mt. Terrill. This route starts out a bit tedious, with lots of boulder-hopping and some minor bushwhacking along the southern slope. I mostly hugged the cliffy rim on the right, where the views toward Mt. Terrill and back toward Mt. Marvine were really neat. It seems like the bushwhacking is worse the closer to the cliffs you get, but I'm not sure. Eventually the trees disappeared and I was greeted by a much more pleasant grassy slope that led to the summit of Mt. Terrill.

On Mt. Terrill, I decided to drop down to the east to a shallow saddle and follow a faint trail rather than heading back the way I came. However, it looked like it could potentially be pretty rocky and unpleasant from above. I love my loops, and preferred to not have to bushwhack back down, so I risked it and am ultimately glad I did. I started north off from Mt. Terrill to avoid its sketchy-looking eastern face, and found a reasonable way down the rocky slopes. It ended up being a really nice side trip, only a few hundred feet requiring some boulder-hopping just before getting to the saddle. The rest of the time, I was pleasantly surprised to find I could hike down and avoid most of the rock outcroppings. Once at the saddle, I was a little annoyed to find the trail was not super obvious, but plenty of social trails led me south down the grassy descent. An old dirt road materialized at about the halfway point, and I followed this back to the Black Flat Trail.

PEAKS ON HIKE
Elevation (ft) / Prominence (ft)
Peaks on hike
Elevation
Prominence
1
Mount Marvine
11610 ft
1850 rise
2
Mount Terrill
11547 ft
1027 rise

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Along the Black Flat Trail. I think this portion was actually re-routed, but it was prettier than just following an ATV dirt road. Mount Marvine visible top left, my first objective.
Along the Black Flat Trail. I think this portion was actually re-routed, but it was prettier than just following an ATV dirt road. Mount Marvine visible top left, my first objective.
Along the remains of the ATV road.
Along the remains of the ATV road.
Pretty tarns along the way.
Pretty tarns along the way.
Still along some old ATV remains.
Still along some old ATV remains.
View back as I continue along the Black Flat Trail.
View back as I continue along the Black Flat Trail.
Eventually the old trail merged with the maintained ATV trail that led me up to UM Pass.
Eventually the old trail merged with the maintained ATV trail that led me up to UM Pass.
Mount Terrill visible top right as I ascend to UM Pass.
Mount Terrill visible top right as I ascend to UM Pass.
Image 7 from gallery
View back as I ascend to UM Pass.
View back as I ascend to UM Pass.
UM Pass.
UM Pass.
Starting up to Mount Marvine.
Starting up to Mount Marvine.
View back as I start up Mount Marvine, Mount Terrill visible top left.
View back as I start up Mount Marvine, Mount Terrill visible top left.
Class 2 boulder-hoppping.
Class 2 boulder-hoppping.
Mount Marvine ahead.
Mount Marvine ahead.
More boulder field hopping.
More boulder field hopping.
After making my way through the boulder field, I found myself on Mount Marvine's southeast slope. I located what seemed to be the least steep option up the Class 2 boulders.
After making my way through the boulder field, I found myself on Mount Marvine's southeast slope. I located what seemed to be the least steep option up the Class 2 boulders.
View back toward the boulder field. Mount Terrill visible top left.
View back toward the boulder field. Mount Terrill visible top left.
Class 2 to the ridge.
Class 2 to the ridge.
After gaining the ridge, I swapped over to Mount Marvine's west side. This is a view south as I continue along Mount Marvine's west side.
After gaining the ridge, I swapped over to Mount Marvine's west side. This is a view south as I continue along Mount Marvine's west side.
Along the Class 2 west side of Mount Marvine's crest. I headed all the way to its north end where I located a reasonable scramble option.
Along the Class 2 west side of Mount Marvine's crest. I headed all the way to its north end where I located a reasonable scramble option.
North side of Mount Marvine, I scrambled up this short Class 3 move to reach the summit.
North side of Mount Marvine, I scrambled up this short Class 3 move to reach the summit.
Mount Marvine summit, view north toward Mount Terrill (top left). UM Pass visible center.
Mount Marvine summit, view north toward Mount Terrill (top left). UM Pass visible center.
Mount Marvine summit, view south.
Mount Marvine summit, view south.
Mount Marvine summit, view east toward Hilgard Mountain. Also, my car is somewhere amongst the tarns in the center of this photo.
Mount Marvine summit, view east toward Hilgard Mountain. Also, my car is somewhere amongst the tarns in the center of this photo.
Back at UM Pass, I started toward Mount Terrill. This is a view back toward Mount Marvine.
Back at UM Pass, I started toward Mount Terrill. This is a view back toward Mount Marvine.
Approaching the south ridge of Mount Terrill. I left the ATV road to ascend when the brush seemed less awful.
Approaching the south ridge of Mount Terrill. I left the ATV road to ascend when the brush seemed less awful.
The initial ascent up Mount Terrill's south ridge swaps between light bushwhacking and Class 2 boulder fields.
The initial ascent up Mount Terrill's south ridge swaps between light bushwhacking and Class 2 boulder fields.
View back, Mount Marvine visible in the distance.
View back, Mount Marvine visible in the distance.
Class 2 with some bushwhacking, but nothing too bad.
Class 2 with some bushwhacking, but nothing too bad.
Image 29 from gallery
The terrain became a little easier. View back toward Marvine.
The terrain became a little easier. View back toward Marvine.
Along Mount Terrill's rim, where the terrain seemed to be a bit more brushy, but the views were nice.
Along Mount Terrill's rim, where the terrain seemed to be a bit more brushy, but the views were nice.
Soon the trees and Class 2 pretty much faded completely and the rest of the ascent to the summit was more gradual and pleasant.
Soon the trees and Class 2 pretty much faded completely and the rest of the ascent to the summit was more gradual and pleasant.
View back along the rim toward Mount Marvine.
View back along the rim toward Mount Marvine.
Ascending to Mount Terrill.
Ascending to Mount Terrill.
Just below the summit, view back toward my progress, Mount Marvine visible on the right.
Just below the summit, view back toward my progress, Mount Marvine visible on the right.
Summit of Mount Terrill. The eastern cliffs (left side in this photo) are too steep to descend directly. I continued north to locate a reasonable way down.
Summit of Mount Terrill. The eastern cliffs (left side in this photo) are too steep to descend directly. I continued north to locate a reasonable way down.
View north rom Mount Terrill.
View north rom Mount Terrill.
A social trail more or less helped me down from the north side of Mount Terrill.
A social trail more or less helped me down from the north side of Mount Terrill.
View back toward Mount Terrill's summit, via the route I came down.
View back toward Mount Terrill's summit, via the route I came down.
I continued east down to the saddle on Mount Terrill's east side.
I continued east down to the saddle on Mount Terrill's east side.
Continuing down on easy terrain.
Continuing down on easy terrain.
A short boulder field slowed me down before reaching the saddle.
A short boulder field slowed me down before reaching the saddle.
View back along the boulder field.
View back along the boulder field.
The saddle visible in the center. Once at the saddle, I headed south.
The saddle visible in the center. Once at the saddle, I headed south.
At the saddle, a very old trail. I headed south.
At the saddle, a very old trail. I headed south.
Continuing south along a sometimes difficult to follow trail, but animals seem to have carved a route, making it pretty easy overall. Mount Marvine visible top right.
Continuing south along a sometimes difficult to follow trail, but animals seem to have carved a route, making it pretty easy overall. Mount Marvine visible top right.
View back up toward Mount Terrill as I descend.
View back up toward Mount Terrill as I descend.
Heading back to the Black Flat Trail, which I took back to my car.
Heading back to the Black Flat Trail, which I took back to my car.

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