Dusting pits are actively used in the period of nesting. At Umiat (June 25, 1952), ptarmigan were using seven dusting pits on the shoulder of the airstrip. On the upland at Kaolak River (July 12, 1951), ptarmigan developed dusting pits on abandoned diggings made by Arctic ground squirrels. Most of the mounds were covered with mosses and lichens and other vegetation. Individuals and family groups were noted at various localities on the Arctic Slope. At Kaolak River (July 15, 1951) on a four hour field trip, we saw three pairs of birds and their families of four to six young. One flock of eight adults was seen from the air at the mouth of the Canning River Canyon on July 22, 1952. At Kaolak (July 21-27, 1951) they were common; ten pairs of adults (males and female) were within a one mile radius of our camp. The families of young were in groups of 1-3-4-6-8-9-10-11-14. One group consisted of one male, two females and four young. While on a flight from Kaolak to Point Barrow (July 27, 1951) we observed several ptarmigan on the tundra. At Gavia Lake (Aug. 21, 1951) ptarmigan were in groups or singles as follows: two adult singles, group of seven young and one adult, group of four young and one adult and one group of five young and two adults. According to Harmon Helmericks, ptarmigan were high in population numbers on the Arctic Slope in 1952. Ptarmigan were associated with most of the communities of the Arctic Slope but were noted more commonly in the following situations than elsewhere: At Kaolak (July 21-27) and at Kaolak River (July 21, 1951) in damp swales of grasses and sedges in poorly drained areas where soils were damp to supersaturated and among the dwarf willows bordering lakes and creeks; at Gavia Lake (Aug. 21, 1952) among willows and alders (4 feet high) along the edges of ox-bow lakes. On windy, cold days the ptarmigan were mainly on south exposures among grasses and sedges along lakes and on windless days were on flat tundra of polygons but near dwarf shrubs. On June 27, 1/5 mile northwest of Mount Umiat, two dead willow ptarmigan were noted along the edge of a willow and cotton-grass swale. The feathers had been plucked by a raptor (?) preparatory to his eating the ptarmigan.