The water flows underground folowing an unknown path. Geologists speculate the water travels through many cracks and fissures created in the water-soluble limestone until it rises to the surface in this calm pool.

The Rise is an active geologic formation that changes from year to year. Erosion in the river and underground alters water flow patterns and changes the amount of sand flowing into the pool. Some years the sandbar is almost gone and some years it takes up part of the upper end of the Rise.

Shaped by ice-age glaciers and the power of the river. Sinks Canyon has served as a natural travel corridor for wildlife and people for thousands of years. Known to Native Americans for centuries, the first white to see the Sinks and Rise were fur trappers. The name Popo Agie (pronounced Po-Po-zsha) is a Crow Indian word which means “Grass River.”

The Rise was donated to the City of Lander in 1969 by Pacific Power and Light Company. The site is now part of Sinks Canyon State Park administered by Wyoming State Parks and Historic Sites.