This is one of the premier hikes for the Big Horn Mountains - a must do, if you want to experience the best the mountains have to offer. The trail starts easy through a very old lodgepole timber stand. It evolves into a steep climb (a good cardio work-out) up a ridge raised by two opposing glaciers. The top of the ridge gives you great views of the upper alpine area, as well as the ascending valley. About half way up the valley is Mirror Lake. Today it was an intense blue and smooth, affording wonderful photo opportunities with the reflection of the rocks and trees in the lake. There is a slow easy climb up a stunning creek valley, with lots of meandering streams, wildflowers, and moose. This opens to a meadow, where you can see the massive granite cliffs that surround the Lost Twin Lakes. The climb up that final ridge (we called it "Heartbreak Ridge" ) is tough, due to the elevation, but once you crest it, the view of the first lake is stunning. There is no trail to the second lake, just a hard boulder climb, but the second lake is the most rewarding of all. There are 14-18" cutthroat trout there and - surprise! - a sandy beach! Take foul weather gear - a hail storm caught us by surprise on the top of the cliff - very cold and slippery.