The majority of the Fossil-Grizzly mule deer herd winters near Bear Creek and the fork of John Day River and Bridge Creek, in habitats composed of big sagebrush, western juniper, and grassland. Another group winters to the southwest, near U.S. Highway 26, in areas with higher proportions of western juniper. In spring, both groups migrate to ponderosa pine, western juniper, and mixed-conifer forests around the Ochoco Mountains. Other Fossil-Grizzly mule deer winter to the north, near Arrastra Canyon, Dry Hollow, and the fork of John Day River and Muddy Creek, and use a mix of grassland, western juniper, and big sagebrush habitats interspersed with nonnative annual grasses. Summer ranges for migratory individuals comprise higher proportions of big sagebrush, ponderosa pine, and mixed-conifer forest near Eagle Valley and Bald Mountain. One Fossil-Grizzly mule deer in this area only migrated once before remaining on the summer range for multiple years. Mule deer traveling to summer ranges on the Ochoco Mountains often cross U.S. Highway 26 where ODOT recorded an annual average of 74.2 DVCs from multiple deer species from 2010 to 2022 along a 45-mile (72-km) section of road (ODOT, 2023). In 2014, the Pine Creek Complex and Bailey Butte fires burned 30,257 acres (12,245 ha) and 10,277 acres (4,159 ha) of winter and summer habitat, respectively (BLM, 2023a). In 2018, the Jennie’s Peak fire affected an additional 45,975 acres (18,605 ha) of winter habitat. These fires occurred in a mosaic of habitat types, potentially spreading invasive grasses in areas without sufficient perennial plant cover, but also beneficially reducing dense canopy cover in heavily forested areas. These mapping layers show the location of the winter ranges for mule deer (Odocoileus hemionus) in the Fossil-Grizzly population in Oregon. They were developed from 73 winter sequences collected from a sample size of 32 animals comprising GPS locations collected every 5-13 hours.