Rainbow Bridge became more accessible with the popularity of river running in Glen Canyon after World War II, although the trip still required several days floating the Colorado River plus a six-mile hike up-canyon. By the early 1950s, people could travel upstream by jet boat from Lee's Ferry. Glen Canyon Dam was authorized in 1956. By 1963, the gates on the dam closed and rising Lake Powell began to engulf the river and its side canyons. Higher water made motorboat access to Rainbow Bridge much easier, bringing thousands of visitors each year.