Lake Powell

Lake Powell

Glen Canyon, drowned by Glen Canyon Dam, now the Upper Basin's great reservoir.

Map of the Lake PowellLake PowellHenry MountainsColorado RiverNavajo Mountain 10,346 ftMount Ellen 11,522 ftMount Hillers 10,723 ftHanksvilleHiteBullfrog / Halls CrossingEscalante (Hwy 12)Mexican HatRainbow BridgeAntelope CanyonLees FerrySan Juan RiverEscalante RiverDirty Devil RiverNavajo CreekWahweap CreekBullfrog CreekNorth Wash25 miles
Lake Powell. River lines from the USGS National Hydrography Dataset.
A bend in Glen Canyon of the Colorado, about 1898, long before Lake Powell.
A bend in Glen Canyon of the Colorado, about 1898, long before Lake Powell.California Historical Society collection, ca. 1898. Public domain · source

People and the river

Glen Canyon at the dam site in late 1957, before construction.
Glen Canyon at the dam site in late 1957, before construction.U.S. Bureau of Reclamation. Public domain · source
Powell's second expedition repairing a boat it had left near the mouth of the Fremont (Dirty Devil) River the year before, 1872.
Powell's second expedition repairing a boat it had left near the mouth of the Fremont (Dirty Devil) River the year before, 1872.Powell Survey (John K. Hillers). U.S. National Archives, public domain · source
  1. For centuriesAncestral Puebloan, Paiute and Navajo people lived and travelled in Glen Canyon.1
  2. Nov 7, 1776The Domínguez–Escalante expedition forded the Colorado at the Crossing of the Fathers, now under Padre Bay.2,3
  3. 1956–1966Glen Canyon Dam was built (after the Echo Park compromise); the river began backing up in 1963.4,5
  4. 1980The lake first reached full pool, 3,700 ft.4

Biggest flows

A butte above the river in Glen Canyon, photographed by Powell's second expedition in 1872.
A butte above the river in Glen Canyon, photographed by Powell's second expedition in 1872.Powell Survey (John K. Hillers). U.S. National Archives, public domain · source
~3,708 ft
record lake level, July 1983, about 3.5 ft below the top of the spillway gates6
measured

Measured: a USGS gauge reading. Estimated: reconstructed after the fact from high-water marks or flood deposits. Provisional: USGS readings not yet reviewed.

Floods that mattered

June–July 1983

A huge snowmelt year filled the lake. Cavitation tore holes in the spillway tunnels, and plywood flashboards on the gates helped hold back the lake until the flood passed.7,6,8

Lake Powell and its Tributaries

Map of Lake Powell and its tributaries in southern Utah and northern Arizona, with Henry Mountains, Kaiparowits Plateau: rivers, side canyons, contour lines and summit elevations, in a classic survey style.
A classic map of the river and the mountains around it. Full size · Vector (SVG) · © 2026 Southwest River Watch
Sources
  1. NPS: Glen Canyon National Recreation Area
  2. Crossing of the Fathers (Wikipedia)
  3. NPS: Crossing of the Fathers, Explorers and Settlers
  4. Bureau of Reclamation: Glen Canyon Unit
  5. Utah Humanities: No Dam Here! The Echo Park controversy
  6. ASDSO: Glen Canyon Dam case study, 1983
  7. Bureau of Reclamation: Glen Canyon Dam spillway damage, 1983 (PAP-0525)
  8. High Country News: 1983 at Glen Canyon Dam

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