Rattlesnake Hills

Rattlesnake Hills
Williamborg 12:54, 29 May 2007 (UTC) · Public domain · source
Name	Rattlesnake Hills
Country	United States
State	Washington
Region	Yakima County

Rattlesnake Hills is a ridge in Yakima County, Washington, forming part of the eastern flank of the Columbia Basin and rising above the Yakima Valley and the Sunnyside area. The ridge is notable for its folded basaltic topography, arid steppe climate, and modern prominence as a viticultural zone and wildlife corridor. It lies in proximity to the cities and towns of Yakima, Washington, Prosser, Washington, and Grandview, Washington, and is intersected by transportation routes linking the inland Pacific Northwest to the Columbia River corridor.

Geography

The ridge trends generally east–west between the Yakima River to the north and the Columbia River to the south, with foothills connecting to the Horse Heaven Hills and the Rattlesnake Hills AVA grape-growing area. Local communities such as Sunnyside, Washington, Grandview, Washington, Toppenish, Washington, and Zillah, Washington border its slopes, while regional landmarks including Yakima, Washington, Prosser, Washington, and the Hanford Site lie within driving distance. Elevational relief produces microclimates that contrast with the adjacent Yakima Valley AVA and Columbia Valley AVA, and the ridge forms part of the drainage divide affecting tributaries feeding the Yakima River and the Columbia River system.

Geology

Geologically the ridge is underlain by the Miocene flood basalts that make up much of the Columbia River Basalt Group, with structural uplift and erosional sculpting exposing layered basalt flows similar to formations mapped near the Grande Ronde Basalt and the Wanapum Basalt. Pleistocene and Holocene loess deposits mantled the basalt in places, comparable to loess mantles found in the Palouse region, while faulting and jointing have influenced rock exposure patterns akin to structures studied at the Cascades Range foothills. Geomorphic processes related to Missoula Floods scouring in adjacent areas have shaped valley floors and colluvial aprons, and soils derived from weathered basalt and loess support the agrarian uses seen on the hills today.

Ecology and Wildlife

The ridge supports shrub-steppe ecosystems characteristic of the inland Pacific Northwest, with plant communities that parallel those cataloged in the Columbia Plateau ecoregion, including sagebrush and bunchgrass assemblages similar to communities preserved at Hanford Reach National Monument and McNary National Wildlife Refuge. Faunal species recorded in the area resemble those of nearby protected areas, with populations of mule deer, pronghorn, coyotes, black-tailed jackrabbits, and various raptor species such as northern harrier, red-tailed hawk, and golden eagle also observed on ridgelines. Reptiles, notably several rattlesnake species familiar from documentation at Saddle Mountain (Washington) and Moses Lake, Washington environs, inhabit rocky outcrops, while migratory songbirds use riparian corridors analogous to those along the Yakima River for breeding and stopover.

Human History and Indigenous Significance

Indigenous peoples of the region, including the Yakama Nation, Confederated Tribes and Bands of the Yakama Nation, and neighboring Plateau groups such as the Wanapum and Umatilla Indian Reservation peoples, historically used the hills for hunting, gathering, and travel, with ethnographic parallels in accounts from the Nez Perce and Coeur d'Alene territories. Euro-American exploration, settlement, and ranching during the 19th century, tied to events like the Oregon Trail migrations and the settlement patterns influenced by the Donation Land Claim Act, altered land use and access. Later 20th-century federal projects and water development initiatives, including works associated with the Yakima Project (Bureau of Reclamation) and irrigation programs paralleling the Columbia Basin Project, further transformed local agriculture and demographics.

Viticulture and Agriculture

The slopes have seen conversion to vineyards and dryland farming, contributing to the agricultural mosaic of the Yakima Valley AVA and the broader Columbia Valley AVA appellations, with grower interests and wineries modeled after producers in Walla Walla, Washington and Prosser, Washington. The viticultural expansion parallels trends represented by the establishment of American Viticultural Areas such as the Rattlesnake Hills AVA and employs rootstocks and varietals also cultivated in Napa Valley and Willamette Valley climates, adapted for semi-arid soils derived from basalt and loess. Irrigation infrastructure connects to regional systems managed by entities like the Bureau of Reclamation and local irrigation districts, supporting orchards, hop yards, and vine plantings similar to agricultural enterprises in Yakima County, Washington.

Recreation and Conservation

Outdoor recreation on the ridge includes hiking, hunting, birdwatching, and scenic drives that echo recreational patterns at nearby sites such as Cowiche Canyon Conservancy, Yakima Greenway, and Ginkgo Petrified Forest State Park. Conservation initiatives by local land trusts, state agencies like the Washington State Department of Fish and Wildlife, and tribal partners aim to balance habitat protection with agricultural and recreational uses, following models used at Hanford Reach and community-based conservation around Toppenish. Efforts focus on preserving shrub-steppe habitat, migratory corridors, and cultural resources identified by the Yakama Nation and state historic preservation programs.

Transportation and Development

Major regional transportation corridors near the ridge include state and U.S. highways linking Interstate 82 and U.S. Route 12 corridors, facilitating movement of agricultural goods to markets such as Port of Pasco and Port of Seattle. Rural development pressures, energy infrastructure siting, and renewable energy proposals mirror planning debates seen elsewhere in Eastern Washington, with participation by county governments, the Washington State Department of Transportation, and local municipalities. Zoning, land-use planning, and economic development efforts involve stakeholders from the Yakima County, municipal governments of Sunnyside, Washington and Grandview, Washington, and tribal authorities working to manage growth while protecting cultural and ecological values.

Category:Mountain ranges of Washington (state)