Sinks Canyon State Park

Popo Agie River Sink

Useful Information

Location: Sinks Canyon, southwest of Lander.
Open: No restrictions.
Fee: free.
Classification: KarstPonor
Light: bring torch
Guided tours:  
Address: Sinks Canyon State Park, 3079 Sinks Canyon Road, Lander, WY 82520, Tel: +1-307-332-3077
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.



Sinks Canyon State Park shows a typical karst phenomenon: a vanishing stream. The Popo Agie River (pronounced Po-po' Zsha) vanishes into a sink or Karstponor, flows about 800 m underground to reappear in a Karstkarst spring, the so called Rise.

The river crosses a patch of Big Horn Dolomite which is karstified. As soon as the water reaches the limestone it starts to form caves. When the soluble rock ends, it is forced to reappear and flow on the surface again. During times of high water in the river, the cave is not big enough to swallow all, so there is an overflow reanimating the old dry riverbed.