and Wyoming gathered in the Indian Heaven area during the summers for annual huckleberry feasts. During these gatherings, they celebrated, traded, and performed rituals; they also raced horses, played various games, constructed baskets, dried meat, tanned hides, and fished in the local lakes. In 1932, the Yakama Nation and the United States Forest Service agreed to set aside a portion of the Berry Fields for exclusive Indian use; the harvest remains an important local tradition. Today, the marks from the Race Track, a meadow used by Native Americans for horse racing, can be seen about off the segment of the Pacific Crest Trail that crosses through the Indian Heaven wilderness. Trees within the area have scars from where their bark was peeled for wood to make baskets. The area is also rich with large game animals and supports a number of roots and tuber plant species. Geology The area near the Indian Heaven vicinity is composed of Western Cascade rocks from the Eocene to Miocene including andesite, tuffs, mud flows, pyroclastic flow deposits, and other volcaniclastic materials, as well as High Cascade rocks that date from between the Pliocene and Holocene epochs. Strata of rock underlying the area has been deformed to create faults, fractures (separations in geologic formation), volcanic igneous intrusions, and a gradual, dipping syncline that trends north to south. The Indian Heaven field resides within the syncline's trough, and it consists of High Cascade rocks, which are far less altered than the surrounding rock strata. Similar to other Cascade volcanoes, the Indian Heaven volcanoes were fed by magma chambers produced by the subduction of the Juan de Fuca tectonic plate under the western edge of the North American tectonic plate. Indian Heaven consists of several, overlapping shield volcanoes that run along a line from Sawtooth Mountain at the north to Red Mountain to the south, as well as cinder cones, lava flows, and spatter cones (low, steep-sided hills or mounds that consist of welded lava fragments). With a total magma output of , the field has about 50 mafic eruptive edifices (rich in magnesium and iron), whose activity lasted from the Pleistocene to the early Holocene. Roughly half of these vents mark a mountainous highland, in length, which runs parallel to the north–south trend of the Cascade Arc in southern Washington state. Most of the volcanoes that comprise the Indian Heaven field are monogenetic, only erupting once