GLEN CANYON — The Bureau of Reclamation and the National Park Service have completed modifications to a warmwater slough in the Colorado River near Glen Canyon Dam removing a key spawning site for invasive smallmouth bass—a growing threat to native fish.  Located 3.5 river miles downstream from the dam and 12 river miles upstream from Lees Ferry, Arizona, the shallow slough within the Glen Canyon National Recreation Area had become a hotspot for warmwater, nonnative fish due to its elevated temperatures. The project involved reshaping the slough to increase water flow and reduce temperatures, creating unfavorable spawning conditions for smallmouth…