This route is probably almost as easy as the route from Mandall Creek and has less elevation gain. It is mostly above timberline though, so a good weather forecast is essential. Once on the long undulating route to the summit, you will be the highest object around during a thunderstorm.
From the trailhead, the trail to Devils Causeway is followed to the saddle just northeast of the causeway itself. From there, the long ridge and plateau area is followed to the summit of “Ptarmigan Flat Top”.
This route is about 11 miles round trip and other than the first 1.5 miles is above timberline the entire way.
From Yampa, look for the sign on the west side of Highway 131 that points the way to "National Forest Access". Turn west on to County Road 7. Follow County Road 7 for seven miles, to where the road becomes FR 900. Stay on the main road for nine miles and drive to the parking area at Stillwater Reservoir. The road is good for all vehicles in day conditions. A 4wd may be needed early or late season.
The winter road closure for the routes above varies. From mid-November through mid-April, the road is closed where the pavement ends (10 miles from Stillwater). In late April, another 7 miles of the road opens allowing access to Bear Lake. In early June (when the snow finally clears) the last 3 miles of the road opens allowing access to Stillwater Reservoir.
This is the trailhead at Stillwater Reservoir.
From the trailhead, follow Trail 1119 along the north side of Stillwater Reservoir. After you are ½ way along the Reservoir, turn right at the junction and continue following Trail 1119. This trail passes Little Causeway Lake after 1.75 miles from the trailhead. The trail steepens here and climbs to the saddle northeast of the Devils Causeway.
Approaching the saddle above Stillwater Reservoir.
From here turn right and follow and indistinct trail up the slope northeast to the summit plateau. The topo map shows a trail along the summit plateau to near the Ptarmigan Flat Top, but there wasn’t much sign of it when I was there in the 2005 or when viewing it in 2012 from the summit.
This is mostly a cross country route across a huge expanse of tundra. Just head north across the miles of tundra to the highpoint. A map and compass/GPS helps, but you can’t get too lost since there are cliffs to the east and steep slopes to the west, so just stay on the plateau top.
Ptarmigans on the summit.
A good pair of boots is needed. Also take a good map and a compass and/or GPS.