" McIntyre also says, that the Basin has the world's greatest diversity of rainbow trout racesdifferent genetic versions of the same species. "The Columbia River, which drains the better half of four states, has eleven different races of rainbow trout. They have looked at about half of the streams in the Klamath Basin and have already found about 15 separate and new races of fish," said McIntyre.
He also believes that this number is in jeopardy. Records kept by his guides documenting the number of fish caught reveal diminishing numbers. McIntyre says that the lack of fish screens on diversion channels is one of the main contributors to this decline. "The fisheries have been harmed irreparably by unscreened diversions. Tens of thousands of fish die in the ditches," he said. Another major contributor to the diminished fishery is the health of Upper Klamath Lake itself." The Lost River - (no date) http://www.wrd.state.or.us/programs/klamath/summary/01.shtml