The Rattlesnake Hills, also known as Rattlesnake Ridge, is a 16-mile (26 km) long

anticline In structural geology, an anticline is a type of fold that is an arch-like shape and has its oldest beds at its core, whereas a syncline is the inverse of an anticline. A typical anticline is convex up in which the hinge or crest is the ...

mountain

ridge A ridge or a mountain ridge is a geographical feature consisting of a chain of mountains or hills that form a continuous elevated crest for an extended distance. The sides of the ridge slope away from the narrow top on either side. The line ...

Yakima County Yakima County is a county in the U.S. state of Washington. As of the 2020 census, its population was 256,728. The county seat and largest city is Yakima. The county was formed out of Ferguson County in January 1865 and is named for the Yakam ...

and Benton County in the

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sover ...

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

. It should not be confused with the much smaller Rattlesnake Ridge located near the west end of

Ahtanum Ridge Ahtanum Ridge is a long anticline mountain ridge in Yakima County in the U.S. state of Washington. It is located just south of the city of Yakima, and much of its length is at the northern edge of the Yakama Indian Reservation. Ahtanum Ridge i ...

just south of

Yakima, Washington Yakima ( or ) is a city in and the county seat of Yakima County, Washington, and the state's 11th-largest city by population. As of the 2020 census, the city had a total population of 96,968 and a metropolitan population of 256,728. The uninco ...

and west of

Union Gap, Washington Union Gap is a city in Yakima County, Washington, United States. As of the 2020 census, the city population was 6,568. Union Gap has become the retail hub for the entire Yakima Valley as a result of Valley Mall and other thriving businesses be ...

. The highest point in the hills (as well as Benton County) is the Lookout Summit, which surpasses the more well-known Rattlesnake Mountain by approximately 100 ft (30 m).Rattlesnake Hills Lookout, Washington
Peakbagger.com The Rattlesnake Hills are part of the

Yakima Fold Belt The Yakima Fold Belt of south-central Washington, also called the Yakima fold-and-thrust belt, is an area of topographical folds (or wrinkles) raised by tectonic compression. It is a structural-tectonic sub province of the western Columbia Plat ...

of east-tending long ridges formed by the folding of

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

Columbia River basalt flows. The Rattlesnake Hills form the northern edge of the Yakima Valley, running from the vicinity of Benton City to just south of the city of

Yakima Yakima ( or ) is a city in and the county seat of Yakima County, Washington, and the state's 11th-largest city by population. As of the 2020 census, the city had a total population of 96,968 and a metropolitan population of 256,728. The uninco ...

, where the

Yakima River The Yakima River is a tributary of the Columbia River in south central and eastern Washington state, named for the indigenous Yakama people. Lewis and Clark mention in their journals that the Chin-nâm pam (or the Lower Snake River Chamnapam Nat ...

cuts through the mountain ridge via

Union Gap Union Gap is a city in Yakima County, Washington, United States. As of the 2020 census, the city population was 6,568. Union Gap has become the retail hub for the entire Yakima Valley as a result of Valley Mall and other thriving businesses be ...

. To the west of the Yakima River the mountain ridge is known as Ahtanum Ridge. North of the Rattlesnake Hills is

Moxee Valley Moxee is a small suburban community southeast of Yakima, Washington. Yakima and Moxee are both north of the Yakama Indian Reservation in Yakima County, Washington, United States. The population of Moxee was 4,326 at the 2020 census. According t ...

and the

Black Rock Valley Black is a color which results from the absence or complete absorption of visible light. It is an achromatic color, without hue, like white and grey. It is often used symbolically or figuratively to represent darkness. Black and white have ...

. The hills extend into the

Hanford Site The Hanford Site is a decommissioned nuclear production complex operated by the United States federal government on the Columbia River in Benton County in the U.S. state of Washington. The site has been known by many names, including SiteW a ...

. A spur on the north side of the ridge nearly connects with the west end of Yakima Ridge. Roza Canal, used for agricultural irrigation, passes under the Rattlesnake Hills through a tunnel. Named high points of the Rattlesnake Hills, according to the USGS, include Elephant Mountain, Zillah Peak, Eagle Peak, High Top, Lookout, and Rattlesnake Mountain. Yakima Fold Belt map

Rattlesnake Hills AVA

The ''Rattlesnake Hills AVA'' is an

American Viticultural Area An American Viticultural Area (AVA) is a designated wine grape-growing region in the United States, providing an official appellation for the mutual benefit of winery, wineries and consumers. Winemakers frequently want their consumers to know abo ...

located in

and

Benton County, Washington Benton County is a county in the south-central portion of the U.S. state of Washington. As of the 2020 census, its population was 206,873. The county seat is Prosser, and its largest city is Kennewick. The Columbia River demarcates the coun ...

Washington state Washington (), officially the State of Washington, is a state in the Pacific Northwest region of the Western United States. Named for George Washington—the first U.S. president—the state was formed from the western part of the Washington ...

. United States

Alcohol and Tobacco Tax and Trade Bureau The Alcohol and Tobacco Tax and Trade Bureau, statutorily named the Tax and Trade Bureau and frequently shortened to TTB, is a bureau of the United States Department of the Treasury, which regulates and collects taxes on trade and imports of alcoho ...

(TTB) awarded Rattlesnake Hills its appellation status on March 20, 2006, making Rattlesnake Hills Washington's ninth federally recognized American Viticultural Area. The Rattlesnake Hills AVA is entirely contained within the

Yakima Valley AVA } The Yakima Valley AVA was the first American Viticultural Area established within Washington state, gaining the recognition in 1983. Part of the larger Columbia Valley AVA, Yakima Valley AVA is home to more than of vineyards, giving the ar ...

, which is in turn is entirely contained within the larger

Columbia Valley AVA The Columbia Valley AVA is an American Viticultural Area which lies in the Columbia River Plateau, through much of central and southern Washington State, with a small section crossing into the neighboring state of Oregon. The AVA includes the d ...

. The hills form the northern boundary of Yakima Valley, and the AVA includes land between the north bank of the

Sunnyside Canal Sunnyside and Sunny Side may refer to: Entertainment * ''Sunnyside'' (film), a 1919 film by Charlie Chaplin * ''Sunnyside'' (novel), a 2009 novel by Glen David Gold * ''Sunnyside'' (Canadian TV series), a Canadian sketch comedy TV series * '' ...

and the entirety of the southern slopes of the Rattlesnake Hills between

Outlook Outlook or The Outlook may refer to: Computing * Microsoft Outlook, an e-mail and personal information management software product from Microsoft * Outlook.com, a web mail service from Microsoft * Outlook on the web, a suite of web applications ...

and the

Wapato Dam Wapato can mean: * Any of various plants in the genus ''Sagittaria'' * Wapato, Washington, a town named after the plant in the State of Washington in the United States * USS ''Wapato'' (YTB-788), a United States Navy tug in service from 1966 to 19 ...

. The AVA is centered on the city of Zillah. With elevations ranging from to , this AVA contains the highest point in the Yakima Valley AVA.

Yakima Fold Belt

The Rattlesnake Ridge is one of the larger "folds" in the

. The Yakima Fold Belt is an area of topographical folds (or wrinkles) raised by tectonic compression. It is a structural-tectonic sub province of the western

Columbia Plateau The Columbia Plateau is a geologic and geographic region that lies across parts of the U.S. states of Washington, Oregon, and Idaho. It is a wide flood basalt plateau between the Cascade Range and the Rocky Mountains, cut through by the Columbia ...

Province resulting from complex and poorly understood regional tectonics. The folds are associated with geological faults whose seismic risk is of particular concern to the nuclear facilities at the

Hanford Nuclear Reservation The Hanford Site is a decommissioned nuclear production complex operated by the United States federal government on the Columbia River in Benton County in the U.S. state of Washington. The site has been known by many names, including SiteW a ...

(immediately north of the Rattlesnake Hills) and major dams on the Columbia and Snake Rivers.

2016 wildfire

The Range 12 fire was started on July 31, 2016, in

eastern Washington Eastern Washington is the region of the U.S. state of Washington located east of the Cascade Range. It contains the city of Spokane (the second largest city in the state), the Tri-Cities, the Columbia River and the Grand Coulee Dam, the Hanfor ...

, at the

Yakima Training Center The Yakima Training Center (YTC) is a United States Army training center, used for maneuver training, Land Warrior system testing and as a live fire exercise area. It is located in the south central portion of the U.S. state of Washington, bound ...

northeast of

. The city it started closest to was Moxee, Washington on July 30, 2016

local time Local time is the time observed in a specific locality. There is no canonical definition. Originally it was mean solar time, but since the introduction of time zones it is generally the time as determined by the time zone in effect, with daylight s ...

. It quickly grew to over to cover parts of

and Benton County. The fire was the third in recent years to affect the area surrounding the

Hanford Reach National Monument The Hanford Reach National Monument is a national monument in the U.S. state of Washington. It was created in 2000, mostly from the former security buffer surrounding the Hanford Nuclear Reservation. The area has been untouched by development or ...

and the Arid Lands Ecology Reserve near Rattlesnake Ridge. The fire was eventually contained through the use of

controlled burn A controlled or prescribed burn, also known as hazard reduction burning, backfire, swailing, or a burn-off, is a fire set intentionally for purposes of forest management, farming, prairie restoration or greenhouse gas abatement. A control ...

s on Rattlesnake Mountain in Benton County due to concerns that the fire was getting too close to the

, which had recently been compared to the

Fukushima nuclear disaster The was a nuclear accident in 2011 at the Fukushima Daiichi Nuclear Power Plant in Ōkuma, Fukushima, Japan. The proximate cause of the disaster was the 2011 Tōhoku earthquake and tsunami, which occurred on the afternoon of 11 March 2011 and ...

Newsweek magazine ''Newsweek'' is an American weekly online news magazine co-owned 50 percent each by Dev Pragad, its president and CEO, and Johnathan Davis, who has no operational role at ''Newsweek''. Founded as a weekly print magazine in 1933, it was widel ...

2018 Rattlesnake Ridge landslide

As of January 21, 2018, a large but slow

landslide Landslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, deep-seated grade (slope), slope failures, mudflows, and debris flows. Landslides occur in a variety of ...

is occurring in the Rattlesnake Hills, about 3 miles south of

, USA. The event first drew news coverage in late 2017, after a long fissure was discovered high on Rattlesnake Ridge: this fissure was reported to be 250 feet deep in one place. The first road closure for public safety was reported on December 17, 2017. The

Washington State Department of Natural Resources The Washington State Department of Natural Resources (DNR) manages over of forest, range, agricultural, and commercial lands in the U.S. state of Washington. The DNR also manages of aquatic areas which include shorelines, tidelands, lands un ...

has a web-page providing information on the event, which reports that the moving mass of

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

is about 4 million tons, covering about 20 acres, and it is slipping roughly south at a rate of about 1.5 feet per week. On the weekend of January 20–21, 2018 there was flurry of new reporting, which highlighted a developing consensus that the landslide will at some time collapse suddenly, and that is likely to occur within months if not weeks.

References

{{Washington State hills and ridges Ridges of Yakima County, Washington Landforms of Benton County, Washington Ridges of Washington (state)