On June 26, 1969, state and local officials met along the Green River at the mouth of Split Mountain Canyon, in Dinosaur National Monument, to dedicate a monument to Major Powell, commemorating the 100th anniversary of his first river trip, and to dedicate the Powell Centennial Scenic Drive, also known as the Powell Memorial Highway. In the absence of any roads closely paralleling the Green and Colorado Rivers except for short distances, this route is virtually the only means of approach to the rivers and comprises parts of several state and federal highways connecting Green River, Wyo., and Grand Canyon, Ariz. A segment of it, U.S. Highway 163, connects Crescent Junction, Moab, Monticello, and Blanding, all in Utah, and provides the principal access routes to Canyonlands and Arches National Parks and Natural Bridges National Monument. The ceremonies at the mouth of Split Mountain Canyon began with the landing of the official party flotilla of four boats similar to the ones used 100 years earlier by Powell, who was impersonated by a bearded man dressed to resemble the one-armed major. After the dedication, the four boats resumed the voyage down the Green River for another ceremony. On June 29 a second monument was dedicated at the head of Desolation Canyon, some 50 miles southwest of Vernal, Utah, where the 1869 Powell expedition first ventured into the then unknown wilderness. The bronze plaque identifies Desolation Canyon, named by Powell, as a national historic landmark that comprises 58,000 acres in an area 1 mile wide on each side of a 95-mile reach of the Green River. [Illustration: Petroglyph] Early History Prehistoric people There is abundant evidence that the canyon lands were inhabited by cliff dwellers centuries before the explorations of Powell or the earlier visits of the Spanish explorers and the fur trappers. Projectile points and other artifacts found in the nearby La Sal and Abajo Mountains indicate occupation by aborigines from about 3,000-2,000 B.C. to about 1 A.D. (Hunt, 1956). Archeologists have found evidence of two occupations by prehistoric peoples in and near Canyonlands National Park—the Fremont people around 850 or 900 A.D. and the Pueblo or Anasazi people from about 1075 to their departure in the late 12th century (Jennings, 1970). Within the park, the most densely populated area was along Salt Canyon and its tributaries in the Needles district, but many prehistoric dwellings and granaries are also found just south of the park in Beef Basin and Ruin Park.