Figure 119: Geographic Features.  Major geographic features described in this chapter are shown above. Two ancient lakes, Grand Lake and Hopi Lake, are superimposed on today’s terrain, shown in nearly true color. The white oval encloses the high Kaibab Plateau, which extends slightly south of the Colorado River. The circle marks the north half of Marble Canyon, about a dozen barbed canyons, the funnel, and parts of Echo Cliffs and Vermilion Cliffs. All will be discussed later. The dashed white line marks the boundary of the uplifted, roughly circular Colorado Plateau, also shown in the insert.

Grand Lake held a volume of water almost twice that of Lake Michigan. The volume of water in Hopi Lake was roughly that in Lake Huron.¹ As the Grand Canyon was carved, water released from water-saturated, flood-deposited sediments may have exceeded the water in both lakes combined.