High Quality Content by WIKIPEDIA articles! Hell`s Half Acre lava field is a basaltic lava plain located on the Snake River Plain of Idaho in the United States. It is the easternmost of the basaltic lava fields on the Snake River Plain, located about 25 miles (40 km) west of Idaho Falls, Idaho and 30 miles (48 km) north of Pocatello, Idaho. In 1976 the National Park Service designated the northwestern portion of the site a National Natural Landmark. In 1986, the Bureau of Land Management recommended that 68,760 acres (27,830 ha) of the site, located just southeast of the National Natural Landmark, to be a wilderness study area.