Numerous river trips were undertaken in the years following Powell’s pioneering expeditions. The ill-fated Brown-Stanton voyage of 1889-90 included starts on both the Grand and the Green Rivers. (See section on “Colorado River.”) More successful were Nathan Galloway and William Richmond, trappers who left Henrys Fork, Wyo., late in 1896 and reached Needles, Calif., on February 10, 1897 (Kolb, 1927, p. 338). Trappers Charles S. Russell, E. R. Monette, and Bert Loper left Green River, Utah, in three steel boats on September 20, 1907; Russell and Monette reached Needles in one boat in February 1908, but Loper was drowned. Dellenbaugh’s 1902 book was carried by the Kolb brothers as a guide for their 1911 trip down the river (Kolb, 1927). In addition to making superb still photographs, the Kolb brothers took the first moving pictures in the canyons, and these are still being shown in the Kolb Studio on the South Rim of the Grand Canyon. Julius F. Stone and party traversed the canyons in 1909, and his account (1932) also contains excellent photographs. E. C. La Rue, of the U.S. Geological Survey, and assistants made two trips down the Green and Colorado Rivers in 1914 and 1915 and additional trips from 1921 through 1924. Their comprehensive hydrographic findings and studies, plus excellent photographs, are given in two reports (La Rue, 1916, 1925). The 1916 report also contains (p. 16-22) a good condensed account of earlier explorations and voyages from 1531 through 1911, taken in part from Dellenbaugh (1902). As noted earlier, a modern river runners’ guide by Mutschler (1969), which logs the Green and Colorado Rivers from Green River, Utah, to Lake Powell, is now available. River mileages in this log were taken from detailed topographic maps of both rivers prepared under the direction of Herron (1917). We will visit only a few notable features of the canyons; the mile-by-mile details for the Green River can be obtained from Mutschler (1969), and those for the Colorado River, from Baars and Molenaar (1971, p. 61-99). Several other references are given below, and additional ones are given by Rabbitt (1969, p. 20-21).