Lily Basin Trail has only one trailhead, so you're looking at an in and out trek. The total elevation difference for Lily Basin Trail is 2,458 feet which is an average number. Lily Basin Trail goes through some very different elevations which of course means you need to be prepared for different conditions on different parts of the hiking and backpacking trail. Keep in mind that this is a long hiking trail, so do pack enough food to last the whole trip. Being 18.6 miles long; it's considered a longer backcountry hike. Now, this is roughly a 3-day walk, so better have big a backpack to fit all the stuff you need.