Excerpt....The subspecific identity of beavers from Utah seems never to have been carefully investigated. With the exception of the name Castor canadensis repentinus applied to animals from Zion and Parunuweap canyons by Presnall (1938:14), all other ... Read more

Excerpt....The subspecific identity of beavers from Utah seems never to have been carefully investigated. With the exception of the name Castor canadensis repentinus applied to animals from Zion and Parunuweap canyons by Presnall (1938:14), all other writers from 1897 until the present time, have used for animals from Utah, the name combination Castor canadensis frondator Mearns, the type of which is from Sonora, Mexico. Study of specimens of beavers from Utah, accumulated in the collections of the Museum of Zoölogy, University of Utah, proves these animals to be far more variable than formerly supposed, and discloses the existence of three hitherto unnamed kinds, which are named and described below. We recognize the need for caution in proposing new names for American beavers, because the transplanting of these animals from one watershed to another may have permitted the animals of a given area to change genetically, say, through hybridization, and may also have altered the geographic distribution of the several kinds. The officials of the Utah State Fish and Game Commission have assured us that such transplants have not occurred in the areas where these three new kinds are found, and further that nowhere in the state have transplants been made from one major drainage system to another; such transplants as have been made were only within the same major drainage system. Less