Buffalo Head Hills kimberlite field grained, and well bedded, with high bedding angles. The reworked kimberlite is well sorted, distinctly bedded, and contains abraded olivine grains. Multiple layers of pyroclastic and reworked kimberlite separated by layers of marine mudstone are present at some pipes. These represent a series of discrete kimberlite eruption events separated by quiescent periods during which the muds were deposited. The majority of the BHH kimberlites are diamondiferous, in contrast to those of the Birch Mountains kimberlite field to the northeast which are mostly barren of diamonds. Based on petrography and whole-rock geochemistry, the BHH pipes are classed as Group 1A kimberlites.
Lemei Rock around Lemei Rock include the Indian Heaven Wilderness, which is known for the high mountain meadows among its scattered volcanic peaks. The Pacific Crest National Scenic Trail passes north/south through the volcanic field and the Indian Heaven Wilderness, which is known for its lakes and views of four nearby volcanoes: Mount Adams, Mount Hood, Mount St. Helens, and Mount Rainier. Major trails at Lemei Rock are the Lemei Trail, which climbs up the east side of Lemei Rock; and Wapiki Trail, which descends from the Lemei Trail to the deep blue Wapiki Lake, the "crater lake" of Lemei Rock. The