There is only one trailhead, so in and out is the way to trek it normally. The total elevation difference for this wilderness trail is 3,151 feet, and that is higher than average. The time needed for this backcountry walk is roughly 6.5 hours, but you never know stuff could go wrong and you could get stuck so be prepared for that. South Pass Lake Trail goes through some very different elevations, so keep in mind that you may need to dress differently at different elevations. Being 7.4 miles long it's an average length hiking trail. This backpacking and hiking trail sometimes gets very dry, so do check for current fire restrictions before you go if you plan to bring a stove or make a camp fire. This is a long backpacking and hiking trail, so don't forget to pack enough supplies.