[10] Color is variable but often includes red, orange or pink on the opercula and throat, bright rosy to drab olive flanks and yellow-orange undersides.

However, due to the loss of populations across their native range and reports of Rio Grande cutthroat in Mexico and Texas, it is unclear how far south this trout once occurred.

The Mexican reports have been all but dismissed, but Garrett and Matlock (1991) provided evidence indicating that Rio Grande cutthroat were likely native to Texas.

Today the southernmost known populations are found on the eastern flanks of the Gila Mountains in Southern New Mexico.

[12] Rio Grande cutthroats currently live on 700 miles of stream in the Santa Fe National Forest, which is approximately 91% of their historical range.