Scientists speculate that there are several mountain passes associated with the headwaters of the Colorado River drainage and Arkansas/Platte River drainages that would have allowed migration of cutthroat trout east of the divide.
Os científicos especulan que hai varios pasos de montaña asociados coas cabeceiras da cunca do río Colorado e do Arkansas/Platte que terían permitido a migración deste peixe ao leste da divisoria.