USFWS · Arizona, California

Imperial National Wildlife Refuge

The Imperial National Wildlife Refuge protects wildlife habitat along 30 miles (50 km) of the lower Colorado River in Arizona and California, including the last un-channeled section before the river enters Mexico. The Imperial Refuge Wilderness, a federally designated, 15,056-acre (60.93 km2), wilderness area is protected within the refuge. It also surrounds the Picacho State Recreation Area. This section of the Colorado River is popular for boating, hiking, fishing, camping, exploring old mining camps and wildlife watching.

From Wikipedia, licensed CC BY-SA 4.0.

Official page at U.S. Fish and Wildlife Service ↗
Imperial National Wildlife Refuge
Photo by USFWS, in the public domain, from Wikimedia Commons.
DesignationNational Wildlife Refuge
Managed byU.S. Fish and Wildlife Service
StatesArizona, California
Size31,453 acres
FWS regionRegion 2
Center point33.09° N, 114.70° W
Night skyVery dark ground, a faint glow at most (Black Marble reading 27)

Boundary map

1 outline

Boundary, simplified to about 0.005 degrees Federal campground

The outline is the agency boundary simplified for display, so small parcels and inholdings may not show. The agency page has the authoritative map.

Weather by month

NOAA climate normals →
Weather by month near Imperial National Wildlife Refuge50°60°70°80°90°100°January: 0.52 inches of precipitationFebruary: 0.53 inches of precipitationMarch: 0.41 inches of precipitationApril: 0.12 inches of precipitationMay: 0.03 inches of precipitationJune: 0.01 inches of precipitationJuly: 0.19 inches of precipitationAugust: 0.38 inches of precipitationSeptember: 0.43 inches of precipitationOctober: 0.20 inches of precipitationNovember: 0.28 inches of precipitationDecember: 0.45 inches of precipitationJanFebMarAprMayJunJulAugSepOctNovDecJanuary: 56.9°F averageFebruary: 60.3°F averageMarch: 66.4°F averageApril: 72.3°F averageMay: 80.0°F averageJune: 88.6°F averageJuly: 94.3°F averageAugust: 94.4°F averageSeptember: 88.8°F averageOctober: 76.7°F averageNovember: 64.2°F averageDecember: 55.1°F average0 in0.5 in1 inTemp °FInches
The line is the average temperature and the bars are average precipitation at Yuma Proving Ground, 25 miles from the center point at 324 feet, station USW00003125 in the NOAA monthly climate normals for 1991 to 2020. Precipitation totals about 4 inches a year.

Large units span more than one climate. The station stands in for the center point, and the outer parts of the boundary can be warmer or colder.

Where to camp

Campsite Atlas →

None of the 1 federal campground within ten miles sits inside the boundary. Nearest first. Distances are from the campground point to the boundary edge, from the Campsite Atlas index.

Most refuges do not allow overnight camping. The campgrounds listed are outside the refuge.

Explore

Guidebooks for Arizona

We earn a small commission if you buy through these links. It does not change what we list.

  • Explore Tucson outdoors
    Karen Krebbs, 2017
    Find at Bookshop.org
  • Camping Arizona
    Bruce Grubbs, 2021
    Find at Bookshop.org
  • Best Tent Camping: Arizona
    Kirstin Olmon Phillips and Kelly Phillips, 2019
    Find at Bookshop.org

Titles come from Open Library's catalog, matched by subject heading or by title.

Reference

Questions people ask

How big is Imperial National Wildlife Refuge?

31,453 acres.

Source: How acreage is computed

Who manages Imperial National Wildlife Refuge?

The U.S. Fish and Wildlife Service.

Source: U.S. Fish and Wildlife Service

What state is Imperial National Wildlife Refuge in?

The boundary crosses Arizona and California.

Source: How states are assigned

Can I camp at Imperial National Wildlife Refuge?

The refuge page says whether camping is allowed here. The federal campgrounds within ten miles are listed under Where to camp.

Source: Where to camp

How do I get to Imperial National Wildlife Refuge?

A point inside the boundary is at 33.087° N, 114.699° W. The official page carries directions and the office address.

Source: U.S. Fish and Wildlife Service

Sources

  • Boundary, name: the U.S. Fish and Wildlife Service refuge boundary layer.
  • States and territories: computed by intersecting the boundary with Census state polygons and coarse outlines of the territories and outlying islands. A place is listed when it holds at least one percent of the area. A boundary that touches no outline is listed under the nearest one.
  • Acreage: geodesic area of the published polygon. The agency’s official acreage can differ where the boundary includes water, easements or inholdings.
  • Photograph: the image Wikidata records for this refuge (Q6006773), the item linked to its Wikipedia article. Author and license come from the file page on Wikimedia Commons.
  • Description: Imperial National Wildlife Refuge on Wikipedia, CC BY-SA 4.0. The article was accepted because its title contains this unit’s name.
  • Campgrounds: the Campsite Atlas index of federal campgrounds, matched to this boundary at build time.
  • Night sky: NASA Black Marble (VIIRS, 2016 composite) sampled at zoom 6 around the center point.
  • Weather, alerts, air quality, river flow and earthquakes load live in your browser from NWS, AirNow, USGS and iNaturalist when you open the page.