In 2017, the Washington Department of Fish and Wildlife updated the management plan for the Sinlahekin Wildlife Area, which encompasses 23,384 acres in Okanogan County, and the nearby Scotch Creek Wildlife Area in north central Washington. The plan, called the Scotch Creek & Sinlahekin Wildlife Area Management Plan, addresses the status of wildlife species and their habitat, ongoing restoration efforts and public recreation opportunities at both the Sinlahekin and Scotch Creek wildlife areas.
Sinlahekin includes seven different management units:
- The Sinlahekin wildlife unit is located south of Loomis and consists of 14,314 acres, including roughly 3,300 acres owned by other government agencies. The Sinlahekin lies within the Sinlahekin Valley, a deep, glaciated canyon with steep rock sidewalls rising from a broad valley floor. The property is within both the Sinlahekin Creek and the Coulee Creek watersheds. Natural lakes, ponds and manmade impoundments offer a variety of fishing and recreational opportunities. Shrub-steppe, wetlands and dry forest are the main habitat types with 40 acres that are being farmed to increase wildlife forage.
- The Buzzard Lake unit consists of approximately 840 acres located 12 miles west of Okanogan. Steep hillsides surround a broad valley bottom where the 12-acre Buzzard Lake rests on the edge of a large meadow. The dominate habitat in the area is a mixed coniferous forest with scattered patches of sagebrush-steppe. The property was purchased in 2009 for critical mule deer wintering habitat. Grazing is being used within the wildlife unit to improve mule deer forage. Buzzard Lake supports a variety of wildlife including black bears, moose, waterfowl, cougars and song birds. Trout fishing draws the highest number of visitors to this property.
- Carter Mountainunit includes 2,000 acres located 7 miles south of Tonasket. An additional 240 acres of land owned by the Bureau of Land Management are located within the unit's boundaries. The terrain varies from broad valleys to rugged, rocky hillsides. Habitat types include shrub-steppe, dry grassland, and dry-mixed conifer forest. Agriculture and grazing have been used to improve vegetation for mule deer. The property was purchased in phases from 2008 through 2012 for mule deer wintering habitat. The unit supports a variety of wildlife including black bears, migratory birds, cougars, bobcats and golden eagles. Mule deer draw hunters to this unit each fall.
- The McLoughlin Falls unit was established by WDFW in May 2012 through jointly funded grants from the Salmon Recovery Funding Board and the U.S. Fish and Wildlife Service. This 165.5-acre property was purchased to enhance riparian and big game habitats. The unit is located about 6 miles south of Tonasket along the Okanogan River. Elevation in the unit ranges from 860 feet to over 1,600 feet.
- Horse Spring Couleeunit consists of approximately 850 acres located 3.5 miles west of Tonasket. The terrain is mostly sagebrush-steppe with rock outcroppings scattered throughout. Narrow, rocky valleys run north-south through the middle of the unit and eroded sandstone hills can be found in the northeast corner of the property, which is also the unit's highest point at 2,200 feet. Habitat types include sagebrush-steppe and dry grasslands – no trees are found in this unit. The property was purchased in 2008 primarily for critical mule deer wintering habitat. The unit provides habitat for a variety of wildlife including whitetail deer, song birds, various raptors, coyotes, badgers and numerous reptiles.
- The Driscoll-Eyhott Island unit consists of about 325 acres of mostly riparian and wetland habitat located one mile south of Oroville, at the confluence of the Similkameen and Okanogan rivers. The unit experiences floods during high water events in spring and early summer due to precarious position between two rivers. The unit was initially established in 1974 to provide goose nesting and foraging habitat. Hay and grain production continues to enhance forage for upland game birds and provides cover for a variety of species. River channels surrounding Driscoll Island provide migration and spawning habitat for steelhead, fall chinook salmon and Osoyoos sockeye salmon.
- The Chiliwist unit encompasses roughly 4,890 acres, located west of the town of Malott. The Bureau of Land Management owns an additional 760 acres within the wildlife unit's boundaries. Chiliwist Creek runs west to east through the unit, which has an elevation ranging from 1,000 feet to nearly 3,100 feet on the top of Chiliwist Butte. Habitat types include shrub-steppe, wetland, riparian, and dry forests. An agricultural lease and grazing permit are used to improve mule deer forage. The Chiliwist was purchased in 1977 primarily for critical mule deer wintering habitat. The Chiliwist also provides habitat for white-tailed deer, black bears, migratory birds, cougars, badgers and coyotes. Upland gamebird hunting is a popular activity on the wildlife area, where forest grouse, Hungarian partridge, chukar, quail and turkey can be found. In July 2014, the Carlton Complex Fire burned through the entire Chiliwist unit. Roads and infrastructure were significantly damaged and it will take years to rebuild what was lost.
Every eight to 10 years, WDFW revises management plans for each of its 33 wildlife areas to document current conditions, address new agency initiatives, and identify new management priorities and actions. In between those major revisions, WDFW updates plans every two years to outline short-term objectives and accomplishments.