In the Park, pocket gophers occur both on mesa tops and in canyons. Most of the localities listed above and others at which mounds were seen are areas of disturbance such as the old burn on Wetherill Mesa, the rights of way for roads, the river valley, and the grazed floor of Prater Canyon. Little evidence of pocket gophers was found on unusually rocky slopes, steep slopes, or in stands of pinyon and juniper or in relatively pure stands of oak-brush. In addition to workability of the soil, the presence of herbaceous plants, many of them weedy annuals, is probably the most important factor governing the success of pocket gophers in a local area. No female was recorded to have contained embryos, but two had enlarged uteri or placental scars. This fact and the capture of nine half-grown individuals indicate breeding prior to late August when most specimens were trapped. Dipodomys ordii longipes (Merriam) Ord's Kangaroo Rat Kangaroo rats have been seen crossing the highway in the Park less than one mile from the Park entrance by Jean Pinkley. Castor canadensis concisor Warren and Hall Beaver In 1935 Quaintance and White spent June 16 to June 20 in the Mancos River Bottoms at the mouth of Weber Canyon, looking for sign of fresh beaver work. They found none. Annual Animal Census Reports include the following information based on patrols along the Mancos River at the east boundary of the Park: 1937--estimate 4 beaver present, 1938--8, 1941--numerous bank burrows, 1942--uncommon, 1944--uncommon, 1945--most concentrated at southeast corner, 1946--runs and two small dams seen (flood had washed out larger dams), 1947--only in 1-1/2 miles north of boundary with Ute Reservation, 1949--two separate colonies (each with dams and one with a large house), 1950--none, owing to drouth and diversion of water upstream completely drying the river at times, 1951--none, 1953--present, 1955--present. On the Mancos River, 6200 ft., in late August, 1956, sign of beaver was abundant, numerous trees had been cut but none within a week, and a bank den was found on the west side of the river extending back 50 feet from the stream and caved in at three places. In 1959 dens were still present. Reithrodontomys megalotis aztecus J.A. Allen Western Harvest Mouse _Specimens examined._--Total, 38: North end Mesa Verde National Park, 7000 ft, 75984-75986; Park Point, 8525 ft., 69316-69317; Far View Ruins, 7700 ft, 69318-69319, 79220, MV 7897/507, and 23 uncatalogued specimens in preservative; 3 mi. N Rock Springs, 8200 ft., 69320-69321; 2 mi. NNW Rock Springs, 7900 ft., 69322-69323; 1 mi. NNW Rock Springs, 7600 ft., 69324; 1/2 mi. NNW Rock Springs, 7500 ft., 69325.