Lost Lake is located south of Cottonwood Pass on the east side of the Continental Divide. There is a small parking area at an old forest service road on Chaffee County Road 306 (CottonWood Pass). A good topographical map will probably show an old jeep trail that serves as the trail for part of the way. Use your map and GPS to navigate the rest of the trail, the first time I tried to find the lake I got "Lost" and did not have a topo map with me and had to hike back out.
Lost Lake is very good for 6-16" native cutthroats. Cottonwood Pass is a paved road and any car can make it to this trailhead. Lost Lake is at Latitude: 38°48'14.70"N and Longitude: 106°24'52.02"W with an elevation of 11,838 ft.
Flies I have had success with at this lake include hopper patterns, ants, stimulators, and griffiths gnat. I did not have any luck with spinners when I went but did catch one on a kastmaster after dark.
To view more pictures of the trails, mines, and lakes check out our Lost Lake Gallery.