Separation Canyon is the steep gulch in the lower Grand Canyon that Seneca Howland, Oramel Howland, and William Dunn climbed as they left John Wesley Powell’s river expedition. The canyon became the threshold of a separation that was both physical and final: the three men set out toward the Mormon settlements of southern Utah, but never reappeared.

Setting and Route

The gulch, later named Separation Canyon, led from the river toward the Grand Canyon’s north rim. On August 28, after watching their companions pass through Separation Rapids and disappear around a bend, the three men climbed out carrying two rifles, a shotgun, a duplicate set of the expedition papers, and a silver watch. Jack Sumner had asked them to deliver the watch to his sister in case he drowned.

From the rim, they crossed the Shivwits Plateau. About thirty arduous miles from the river, they climbed Mount Dellenbaugh, an extinct volcano, to get their bearings and plot a route onward. Dunn scratched his name into a boulder on the summit, 6,990 feet above sea level. What followed is uncertain: the men presumably headed north, but none returned.

The Expedition’s Parting

The departure came after the party had traveled nearly a thousand perilous river miles. With only five days of provisions left, the expedition was under strain, and a rift divided Powell and his brother, Walter, from the five trappers. Powell pleaded with Dunn and the Howlands to stay with the main group, but they announced that they would leave, climb roughly four thousand vertical feet to the north rim, and cross more than a hundred miles of barren country to reach the settlements of southern Utah.

After the remaining boats cleared Separation Rapids, the others pulled ashore. Jack Sumner later recalled that they waited about two hours, fired guns, and signaled for the Howlands and Dunn to come along the cliffs. The three were last seen standing on the reef, signaling for the expedition to continue without them. The canyon thus holds two views of the same break: the departing men looking toward the rim, and their companions waiting below before moving on.

A Name Bound to an Uncertain Disappearance

The climb through Separation Canyon began a journey whose destination and outcome remain unknown. The men carried the means to continue across the plateau, and Dunn left his name on Mount Dellenbaugh, but neither gesture supplies a record of what happened after they left the river. Their disappearance gives the place its narrative weight: it marks the last known passage of the three men and the point at which the expedition’s shared route divided into separate, irrecoverable paths.