There is only one trailhead, so you're looking at an in and out backcountry walk. Coal Mine Trail has a total elevation difference of 3,603 feet, and that is higher than average. Coal Mine Trail goes through some very different elevations, so keep in mind that you may need to dress differently at different elevations. Coal Mine Trail is quite long, so do pack enough food to last the whole trip. Being 10.6 miles long; it's longer than many great outdoors hiking trails. Now, this is roughly a 1.5-day backcountry trek, so better have big a backpack to fit all the stuff you need. Sometimes this backcountry trail gets really dry, so make sure you check current conditions and fire restrictions with local forest authorities before you head out.