Blue Lake Rhino Cave

Useful Information

Location: At Blue Lake, south of Dry Falls. Trail to the caves starts near the north end of Lake Lenore. Start at Laurent's Sun Village resort.
Open: no restrictions [2007]
Fee: free [2007]
Classification: Speleologylava mold Columbia River Basalts
Light: none, bring torch
Dimension: L=2.4 m, VR=1 m.
Guided tours: n/a
Bibliography: Walter M. Chappell, M. J. Wyatt Durham, Donald E. Savage (1951): Mold of a rhinoceros in basalt, Lower Grand Coulee, Washington, Geological Society of America Bulletin 62: 907-918.
Keith L. Kaler (1988): The Blue Lake rhinoceros, Washington Geologic Newsletter 16(4): 3-8.
Arn. Slettebak (1981): Recreating the Blue Lake Rhino Cav, Curator 24(2):89-95.
George F. Beck (1965): The Blue Lake Rhino, Gems and Minerals 334, p. 25, 35.
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
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1935 discovered by hikers.
1936 visited by Walter M. Chappell.
1948 reconstruction by J. Wyatt Durham and Donald E. Savage.


The Blue Lake Rhino Cave is not named after an Rhinoceros, it is one! One of the basalt flows in the Grand Coulee, the Columbia River Basalt, covered a rhinoceros, and now contains a small cave in the former shape of the animal. It is a sort of cast, made by highly fluid, rapid-moving basalt. The legs are four cylindrical holes in the basalt, branching off from the rounded contour of the body.

The rhinoceros was a mature Diceratherium bull from the Miocene. It was grazing on the wide Miocene prairy, when the eruption started. Fleeing from the fast moving lava flow, it was trapped by a lake and thus could not flee. It was probably killed by the heat and the poisonous gases before it was covered by the lava. The water in the body of the animal cooled the rock which hardened in the shape of the body. The lava is the Priest Rapids flow, a member of the Wanapum Basalt series. It was formed about 14.5 million years ago.

The cave is visited from Laurent's Sun Village resort, from where approach by boat or by foot is possible. The boat is a rowboat, which may be rented for a few dollars. Because of its size, the crawl through the cave is not for everyone. However, take a torch with you and you may be able to see the bellybutton.

In the late 1940s a crew from Berkeley made a cast of the interior of the cave. They used jellied soap to coat the interior and then made sector casts of plaster. The cast is on display at the University of Washington Burke Museum in Seattle. Beneath the cave itself some bone fragments were found too. The largest is the left mandible with broken teeth, indicating a mature animal comparable to Diceratherium annectens.