When taking the trail to Snow Lake, as it switches back to the north or northeast and starts to get steep as it ascends the ridge, look for an obvious sign at the split in the trail. The old trail to Snow Lake proceeds westerly ahead aiming at Chair Peak. As you follow this trail branch westerly, at some point you will see Source Lake down below you on your left. You can then work your way down the rockslide to the lake. (It is actually shorter and easier to go down through the trees when you are at the level of the lake, but you probably won’t be able to see it through the trees, and won’t see it easily until you get to the rockslide.)
The lake is stocked periodically with coastal cutthroat. It is a pretty little pot, but is obviously very small and shallow, so consider releasing all your fish, or take only one for dinner.