The Blue Lake Rhino Cave is not named after a rhinoceros, it was one.
The rhinoceros-shaped cave was made by highly fluid, rapid-moving basalt that was once a mature Diceratherium (an ancient ancestor of the modern rhinoceros) bull grazing on prairie when the eruption started. Its escape route was cut off by a lake, which led to the Diceratherium’s fiery fate.
Death by lava sounds like a terrible way to go, but on the bright side, the Diceratherium was probably killed by the heat and poisonous gases before it was eventually covered by the lava. The remaining fluids in its corpse cooled the molten rock, which hardened it into its present shape.
In the late 1940s a crew from Berkeley made a cast of the interior of the cave. The cast is on display at the University of Washington Burke Museum in Seattle. Some bone fragments were found. The largest is the left mandible with broken teeth, indicating a mature animal comparable to a Diceratherium ancestor.
Because of its size, a crawl through the cave is not for everyone. However, if you take a flashlight with you, you may be able to see the bellybutton.
Know Before You Go
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 From there, approach by boat or by foot is possible. The boat is a rowboat, which may be rented for a few dollars.Keep in mind that you should wear jeans or sportswear that can take a beating as coming down on your bottom in places is probably safest because of loose rocks. Also bear in mind that this landscape is continually changing because of the extreme heat and cold. Rocks split and easily break off so be cautious when selecting handholds.
Making it to the cave is fun and easy for most. To actually go further up to see the rhino can be inherently dangerous in a number of spots and not recommended unless you are familiar with rock climbing, the landscape, and the nature of the area. Safety first!