Lost Lake is a lesser known spot off of Cottonwood Pass, that sends you through some forested areas and meadows, that eventually lead to an alpine lake.
This Trail starts at about 11,200 feet right before the top of cottonwood pass. The trailhead starts at the LAST pull-off before you reach the top of the pass, so if you reach the top, you've gone too far. The hike isn't a super difficult one, but you will go through numerous streams and flooded meadows (depending on the time of year). The view from the top looks straight down the valley and from the top of the lake you can see Pikes Peak in the distance on a clear day.