From the Mount Evans parking lot (just past Echo Lake), descend gradually until you see a trail sign for Chicago Lake trail.  Continue to descend down a fairly technical rocky stretch of trail until you cross Chicago Creek and hit a road.  Turn left and head up the road towards Idaho Springs Reservoir (which also has fish in it, but we didn't fish on the way up...).  

At the end of the lake is a strange, militant person's house.  If he is outside, he is just looking for attention. Don't engage.  

Continue up and up and up until you see Lower Chicago Lake down on your left.

We did not see an easy way down to the lake through the willows, so we just bushwhacked.  Super windy, but managed to catch a cutthroat pretty quickly on a hothead black leech pattern.