Tonto Basin

Tonto Basin. Roosevelt Lake's Watershed. Over six million years ago, the mountains surrounding you were lifted skyward. As they rose, the land in between sank, creating the valley known as Tonto Basin., Melting snow and summer rains drain from the vast Salt River watershed toward the basin. Countless thousands of years of erosion carved numerous canyons and arroyos throughout the mountains., The Salt River enters Roosevelt Lake from the east. Carrying runoff from melting snow and rain from across northeastern Arizona, the Salt River is at times a raging torrent. Tonto Creek enters the valley from the north, merging with the Salt River where the Roosevelt Dam now stands. The construction of Roosevelt Dam enabled downstream communities to manage and control downstream water delivery.