recorded. Most of the cultural remains found are chipped stone tools (lithic materials), including projectile points, scrapers, drills, knives, choppers, and ground stone tools and manos (grinders). The collection of sherds are mostly Tusayan Gray Ware and Tusayan White Ware. Petroglyph panels are found throughout Glen Canyon. "Pecked and incised figures depict mountain sheep, human figures, birds, human handprints and animal tracks. Geometric figures range from circles and spirals to highly complex rectilinear patterns. The human figures have triangular bodies. Painted figures have been reported for both sides of the river.... Petroglyph panels of such quality are lacking from the highland regions adjacent to Glen Canyon". Historic period The recorded history of the canyon begins with the Dominguez–Escalante expedition in 1776, during which Spanish explorers first documented the existence of Glen Canyon. The expedition members crossed the Colorado River in Glen Canyon at the site now known as the Crossing of the Fathers. In the 1830s, trapper Denis Julien may have visited upper Glen Canyon by boat. In 1869 and again in 1871, scientific expeditions led by John Wesley Powell traveled through Glen Canyon en route to the Grand Canyon, resulting in the first formal surveys of the main channel and many of the side canyons. In the 1890s, hundreds of miners panned for flour gold in Glen Canyon. Their main camp was at Dandy Crossing, also called Hite, Utah, after Cass Hite. Between 1898 and 1901, mining engineer Robert Brewster Stanton was employed by mining magnate Julius Stone to design, build, and operate a dredge in an attempt to recover Glen Canyon's flour gold. The effort failed. Geographical and cultural features The following is a list of geographical and cultural features along the Colorado River in Glen Canyon. Many of these locations are now partially or entirely submerged beneath the waters of Lake Powell. River mileage is derived from the USGS 1921 Plan and Profile maps. River Mile Zero is at Lee's Ferry, Arizona; the numbers increase as one travels upstream, ending at Mile 169.6 at the confluence with the Dirty Devil River. Glen Canyon Dam In the 1950s, with the proposal of a dam upstream of the Grand Canyon for water storage and hydroelectric power generation, many environmentalist groups rallied to prevent the inundation of the largely undeveloped canyons in the upper Colorado River watershed. The Sierra Club and its leader, David Brower, were instrumental in blocking the