_=Clethrionomys gapperi uintaensis=_ Doutt. Red-backed Mouse.--Previously, the red-backed mouse in Utah was known only from the Uinta and Wasatch mountains. The southernmost localities from which specimens were available were in northern Wasatch County and southern Salt Lake County. Durrant (1952:355) supposed that the species ranged southward to Mount Timpanogos in Utah County. One specimen, No. 10,075, from the summit, 18 miles east of Mayfield, Sanpete County, and 4 from Ephraim Canyon, 15 miles east of Ephraim, Sanpete County, show that this subspecies occurs also on the Wasatch Plateau of central Utah. These latter specimens extend the known range of the red-backed mouse in Utah approximately 100 miles southward. Owing to the practically continuous nature of the central mountain ranges of Utah, students of mammals of Utah usually suspect that most montane mammals occur throughout these mountain ranges. The red-backed mouse has been sought for in vain in the mountains south of the Wasatch Plateau. Suitable habitats for this mouse occur throughout the Fishlake Mountains, Thousand Lake Mountains and the Aquarius Plateau, but despite intensive collecting, none has been obtained from these areas. _=Phenacomys intermedius intermedius=_ Merriam. Heather Vole.--The heather vole, while not rare, is uncommon in Utah. Durrant (1952:360) had but eight specimens from various localities in Summit, Wasatch, Salt Lake and Utah counties and supposed that the species was restricted to the western Uinta Mountains and southern Wasatch Mountains. In the summers of 1952 and 1953, intensive collecting of mammals was carried out on Boulder Mountain and the Aquarius Plateau, in Wayne and Garfield counties. Two specimens, nos. 8956 and 9074, were obtained from Spectacle Lake, Boulder Mountain, Garfield County. These specimens extend the known area of occurrence 175 miles southward in Utah. No specimens are known from the areas between Mount Timpanogos in Utah County, and Boulder Mountain in Garfield County. We suspect, however, that when this intervening area has been thoroughly studied, the heather vole, like many other montane mammals, will be found throughout the entire length of the central mountain ranges.