The Popo Agie River is flowing into the Madison Limestone formation,
a soft sedimentary rock. The water is flowing into many cracks
and fissures in the soft limestone. It takes the water over 2-hours
to make the journey to the "rise" no more that 1,500-
feet down the canyon.
Geologists think that the water takes so long because the underground
passages are small and wind under the canyon floor like a maze.
Most of the year about 100-cubic feet of water per-second flows
into the sinks. During spring run-off the Pogo Agie swells to
over 500-cubic feet per-second. This much water flow is more than
the sinks can handle in the underground labyrinth of tunnels.
The underground passages can't handle the flow and the excess
spills over and runs down an over flow channel (dry most of the
year) until it meets up with the Pogo Agie downstream of "The
Rise".
The Pogo Agie River has formed Sinks
Canyon over millions of years by the process of erosion.
The Rise is the pool where the water from "The Sinks"
reappears.
Look closely in the pool, those dark spots are large rainbow
trout. They are protected here.
This is another picture of the pool formed by "The Rise"
of the Popo Agie River.
Large rainbow trout in "The Rise" pool
of the Pogo Agie River in Sinks
Canyon Lander,
Wyoming
Large rainbow trout in the "Rise" of the Pogo Agie
River.
Large Rainbow trout in the pool at "The Rise" of the
Popo Agie River Sinks Canyon
Lander,
Wyoming
Rainbow trout at "The Rise" pool of the Popo Agie River.
This is the Popo Agie River downstream of "The Rise"
as it flows through Sinks
Canyon on its way to Lander
and eventually the Little Wind River near Riverton, Wyoming.
