The original and only natural range of the rainbow trout and steelhead was the Pacific coast from northern Mexico to southeastern Alaska and inland to the tributaries of the Columbia and Snake Rivers as far as the Clearwater and Salmon Rivers of Idaho. The steelhead and rainbow coexisted in this range and they are virtually indistinguishable. Most coastal streams still have very small populations of slow-growing, non-anadromous rainbows who usually exhibit life histories that feature migration from a small stream to a larger river or to a lake.