It is on the sawtooth society map, close to galena summit. Beautiful hike, about two miles from car and amazing scenery at the lake. Says mike blomquist
Mill Lake is located in the Sawtooth Range. This lake is so wonderful. Stay the night at Prairie Campground, and a spree to Sawtooth National Forest when you're here is never a bad idea. You'll never forgive yourself if you donít go skiing at Sun Valley while you're here. You'll need more than a
day to discover everything Mill Lake has to offer, you can camp at East Fork Baker Creek. You can never get enough of the tremendous skiing at Soldier Mountain.