From the Boulder Daily Camera (Jeff Milton):
To avoid the extirpation of Colorado River cutthroat from Trappers Lake, CDOW biologists decided to manage the trout by selectively trapping fish and removing brookies. The Fyke nets used resemble a gigantic minnow trap with a net curtain extending 50 feet from the mouth of the trap to shore. When a fish encounters the curtain it turns toward deeper water to get around the obstruction. Swimming along the wall of netting, the fish passes through a series of funnels culminating in a confined space with netting on all sides. Biologists empty the trap nets and remove brookies while returning cutthroat to the lake. Culled adult brook trout are cleaned, packed in ice, and taken to the food bank in Meeker.
By setting traps and leaving them overnight for a half dozen nights each fall, biologists have cut the percentage of brook trout in the population in half. The cutthroat are safe as long as the management program continues. Regrettably, there is no realistic prospect of eradicating the brookies.
More White River Basin coverage here here.