Spawning occurs in the upper reaches of mainstem and tributary streams from late August through October. Eggs incubate in the gravel through the fall and winter and emerge during the spring. Two types of Bull Trout populations exist. One completes its life cycle within the upper reaches of its natal stream system. In the other population type juveniles again rear in the upper reaches of stream systems but migrate after two to three years to reside in lower areas of mainstem Grande Ronde, Snake and Imnaha Rivers where larger prey is more abundant.
Mature fish move back upstream in late spring and early summer to spawn the following fall.
Birkmaier has ranched all his life, and follows in the footsteps of family before him. One of his sons, Tom, is actively working on the ranch and will continue the family tradition. The Birkmaier Ranch is located 31 miles northeast of Enterprise at the confluence of Chesnimnus and Crow Creeks where they become Joseph Creek. The Ranch combines private land with Federal grazing allotments to feed their cattle. It is a personal goal for me as it is for many of our neighbors to leave the land to our children in better shape than we found it.