The Murderer’s Creek mule deer herd winters south of U.S. Route 26 in river valleys near Canyon Creek, Murderer’s Creek, and the South Fork John Day River. The herd’s winter ranges are characterized by western juniper, big sagebrush, and Columbia Basin grassland communities, with medusahead and other non-native grasses invading lower elevations. In the spring, mule deer mainly migrate southeast to summer ranges distributed throughout Gilbert Ridge and the Aldrich Mountains, some traveling as far south as Devon Ridge and east to Ironside Mountain. Summer ranges in these areas contain mixed-conifer forests, ponderosa pine, and low sagebrush communities. A smaller portion of this herd migrates northeast in the spring, crossing U.S. Route 26 to summer in the foothills of Long Creek Mountain, the Blue Mountains, and Elkhorn Ridge, in areas containing big sagebrush along with Populus tremuloides (quaking aspen), ponderosa pine, and mixed-conifer forests. In areas of low-quality browse, Murderer’s Creek mule deer that migrate or reside south of U.S. Route 26 can compete with feral horses, particularly during drought years. The Murderer’s Creek Herd Management Unit (HMA) currently contains 329 feral horses (BLM 2023), significantly more than the maximum appropriate management level of 140 horses (USFS, 2009). In 2010, the Murderer’s Creek Wildlife Management Unit (WMU), which overlaps the Murderer’s Creek HMA, was included in the Mule Deer Initiative to improve conditions for mule deer, primarily through habitat restoration (ODFW, 2011). Since 2010, ODFW has treated 17,295 acres (6,999 ha) for western juniper removal and reseeded 10,016 acres (4,053 ha) for native shrubs and grasses, in addition to temporarily closing 128 mi2 (332 km2) of road within the Flagtail Travel Management Area during hunting season (ODFW, 2015, 2020). In 2015, the Canyon Creek Complex fire burned 110,261 acres (44,621 ha) across the Aldrich Mountains, reducing canopy closure and further improving habitat in summer ranges. The number of Murderer’s Creek mule deer is now stable with a 2021 estimate of 5,568 mule deer (ODFW, 2021). These mapping layers show the location of the winter ranges for mule deer (Odocoileus hemionus) in the Murderer's Creek population in Oregon. They were developed from 185 migration sequences collected from a sample size of 116 animals comprising GPS locations collected every 5−13 hours.