According to Annie Proulx, Jack and Ennis spent their questing days in the:
Big Horns,
Medicine Bows,
Gallatins,
Absarokas,
Granites,
Owl Creeks,
Bridger-Teton Range,
Freezeouts,
Shirleys,
Ferrises,
Rattlesnakes,
Salt River Range,
Wind Rivers,
Sierra Madres,
Gros Ventres,
Washakies,
Laramies,
Hail Strew River;
but never returning to Brokeback.