Originally Posted by
Natural Lefty
Actually, Rainbow Trout are native to this region, including where Silverwood Lake is now, I think. The other species all come from east of the continental divide.
And no, fish don't just show up on their own in new watersheds unless something drastic happens, like streams changing course. Rainbow Trout are native to various SoCal watersheds because they are able to go to sea and migrate up different streams, plus when the oceans were lower, streams that now do not meet used to confluence so that fish could swim from one to the other.