The Island Park area is an ancient volcanic caldera with scenic mountain ranges replete with creeks & springs that drain into the Henry's Fork of the Snake River Henry's Lake & the Island Park Reservoir. The landscape is dominated by lodgepole pine and Douglas-fir forests, scattered stands of aspen trees, & open meadows.
Once you leave the agricultural Upper Snake River Valley outside of Ashton, Idaho, you'll actually be driving up the edge of the caldera, a collapsed volcano. Once you're on top, the landscape is relatively flat with rolling hills and surrounded by mountains. The former caldera is 18 miles long, 23 miles wide and is marked by a 1,200 foot scarp on the south and west rims.