The dam and reservoir have fragmented the upper Green River, blocking fish migration and significantly impacting many native species. Water released from the dam is generally cold and clear, as compared to the river's natural warm and silty flow, further changing the local riverine ecology. However, the cold water from Flaming Gorge has transformed about of the Green into a "Blue Ribbon Trout Fishery". The Flaming Gorge Reservoir, largely situated in Flaming Gorge National Recreation Area, is also considered one of Utah and Wyoming's greatest fisheries.