Escalante River

Escalante River

The last river of its size to be mapped in the lower 48 states, cutting a maze of slickrock canyons to Lake Powell.

Map of the Escalante RiverBoulder MountainFiftymile MountainEscalante RiverBluebell Knoll 11,328 ftEscalanteHwy 12 bridgeBoulderHarris WashCoyote GulchLake PowellPine CreekSand CreekBoulder CreekMoody CreekDeer CreekTwentyfive Mile WashBirch CreekSilver Falls Creek10 miles
Escalante River. River lines from the USGS National Hydrography Dataset.

People and the river

Photographer John K. Hillers at work on the Aquarius Plateau, where the Escalante begins, 1870s.
Photographer John K. Hillers at work on the Aquarius Plateau, where the Escalante begins, 1870s.Powell Survey. U.S. National Archives, public domain · source
  1. For centuriesFremont and Ancestral Puebloan people farmed and stored grain in its canyons.1
  2. 1866A cavalry patrol under Capt. James Andrus reached the headwaters near the present town of Escalante.2
  3. 1872Almon Thompson of Powell's survey mapped it and named it for the 1776 Domínguez–Escalante expedition, the last major river discovered in the contiguous U.S.2,3
  4. 1996Most of its canyons became part of Grand Staircase-Escalante National Monument.1

Biggest flows

~7×
the largest gauged flood: the biggest flood found in sand left in the canyon's alcoves, about 900–1,000 years ago. Its flow in cfs was never published; nine floods from about A.D. 450–1550 are dated but not measured.4,5
estimated
17,700–20,100cfs
One of four floods from 1909 to 1940, the largest since settlement, reconstructed from flood deposits near the town of Escalante. They cut the river's arroyo up to about 55 ft deep and 330 ft wide; the first, on Aug 31, 1909, destroyed the USGS gauge.5,4
estimated
~2,560cfs
Escalante River near Escalante, Aug 31, 2026, 117 years to the day after the 1909 flood took out the first gauge.6,5
provisional reading

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

2006

Floods destroyed most of the roads in Grand Staircase-Escalante National Monument.7

Clustered floods

Canyon deposits show big floods bunched around 1,000 and 500 years ago and again in historic times.4

The Escalante River and its Tributaries

Map of the Escalante River and its tributaries in south-central Utah, with Boulder Mountain, Fiftymile Mountain: 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. BLM: Grand Staircase-Escalante National Monument
  2. Escalante River (Wikipedia)
  3. American Rivers: Escalante River
  4. Webb (1985): Late Holocene flooding on the Escalante River
  5. USGS SIR 2020-5065: Flood-frequency estimation for very low annual exceedance probabilities (Escalante River case study, table 8)
  6. NOAA National Water Model archive of USGS 15-minute readings (provisional)
  7. NWS: Flood safety in Utah

Southwest River Watch · Headwaters · Terms