Benton County was created out of Klickitat County on March 8, 1905.
Benton County is located in the southeastern portion of Washington state at the confluence of the Columbia, Snake, and Yakima rivers. The land, part of the semi-arid Columbia Basin, lies in the rain shadow of the Cascade Mountains and is naturally dry. But the soil is fertile and supports native plants such as bunch grasses and sagebrush. This vegetation in turn supported the deer and elk that Native Americans hunted, and later, the cattle and sheep of white settlers. Irrigation began in the 1890s with water drawn from the Columbia River. Farm crops then flourished, including wheat, alfalfa, grapes, strawberries, and potatoes. That same Columbia River was one factor that caused the federal government to choose Benton County for a secret wartime plant, the Hanford Works, that would develop plutonium for the atomic bomb. After the war, Congress created the Atomic Energy Commission, which took over operation of the 600-square-mile Hanford Atomic Reservation, and work continued on government projects that included the use of nuclear energy to generate electricity. Today the county's two main industries are nuclear power and agriculture. Wineries are growing in importance.
The first inhabitants were the Yakamas, Umatillas, Klickitats, and Wallulas. These native people fished for salmon and steelhead in the rivers, hunted elk and deer in the hills, and gathered seeds, roots, and berries. The "Indian Wars" of the 1850s involved some of these tribes, but the fighting took place in other parts of the state. After the wars were over and the tribes began to be settled on reservations, more large scale settlement by non-Indians began.
In 1858, a gold rush to British Columbia brought the first influx of white people, as rushers traveled through on their way north. A ferry service developed in the northern end of the county in the area that would be known as White Bluffs. By the 1870s, ranchers occupied formerly empty spaces with large cattle herds. Ben Rosencrance homesteaded one of the first ranches near the mouth of the Yakima River where the future town of Richland would develop. John B. Schwitzler and Jade Schwitzler raised large herds of horses in the southern part of the county.
During the 1880s, steamboats and railroads connected what would become known as Kennewick to the other settlements along the Columbia River. The Northern Pacific built a new station in the western part of the county at the future Kiona, in 1888. Now that farmers could get their produce to market (the main crops were corn, wheat, alfalfa, potatoes, and fruit, especially apples), more were encouraged to settle in the area. Colonel William F. Prosser and his wife Flora settled in the western part of the county. Lewis Hinzerling built a flour mill nearby. In 1905, Benton County was carved out of the eastern portions of Yakima and Klickitat Counties. The new town that had grown up around Hinzerling mill, Prosser, was chosen as county seat.
Benton County has very little rainfall, and some farmers had been successful at dryland farming. Irrigation came to the county in the 1890s and brought many changes. The Yakima Irrigating and Improvement Company built the first canal in the 1890s. The canal carried water from the Yakima River to Kiona. The Northern Pacific Irrigation Company installed pumps and ditches to irrigate the Kennewick Highlands, to provide water for orchards, in the 1900s. In 1905, the Benton Water Company completed a canal from the Yakima River to north Richland. Pacific Power & Light was the company that supplied electricity for the irrigation pumps.
Once there was a reliable water source, orchards and vineyards sprung up all over the Kennewick area. Strawberries were another successful crop. Canals also fed Richland and White Bluffs. When electricity arrived in the 1910s, irrigation improved even more because electric pumps filled the canals.
In 1906, the Hanford Irrigation and Power Company was formed. The town of Hanford rose seven miles downriver from White Bluffs. In 1910, fire destroyed the business district but the town bounced right back with more businesses and farms.
Water transportation provided regular passage of the mail and shipping goods to market. Regular ferry service connected White Bluffs with the rest of the state. Ferry service also connected the Plymouth area to Umatilla and other Oregon communities on the other side of the Columbia River.
Railroads brought more change to the county. In 1908, the Spokane, Portland & Seattle Railway completed a railroad along the north bank of the Columbia River at the southern part of the county near the town that would become known as Plymouth. Several miles down river, the small town of Paterson developed around the railroad station on the same route. The Oregon-Washington Railroad and Navigation Company decided to build a new railroad across the Yakima River from Kiona in 1907. The new community of Benton City sprang up around it. The railroad came to White Bluffs in 1912 and to Hanford in 1913.
Herbert A. Hover, president of the Kennewick Land Company, began promoting the acres of land southeast of Kennewick in anticipation of a big boom. Many families moved to this new development southeast of Kennewick, including George Finley. Both men would have communities named for them, as the small towns of Hover and Finley expanded in anticipation of a big building boom. However, the railroad chose another town for the terminal. Also a new bridge was built between Pasco and Kennewick. Both these events ended the boom in Hover and Finley.
Another development was the discovery of oil resources in the Rattlesnake Hills. The largest hill in this range, Rattlesnake Mountain, dominates the county landscape, with its highest peak reaching some 3,560 feet. Throughout the 1910s and 1920s various companies drilled in this area for oil and natural gas. There were no large findings and the Great Depression put an end to exploration.
In the western part of the county, Prosser was growing. Irrigated fields brought more farmers to the area. At the turn of the century, there were already numerous real estate offices, banks, and mercantile establishments. A permanent court house was built in 1926. Prosser boasted three newspapers, which were consolidated in the 1920s into the Prosser Record-Bulletin. Area farmers produced several varieties of apples with great success.
Growth in the county was slow but steady. During the Great Depression, many people lost their businesses. Plymouth became a ghost town. The railroad never did come to Benton City and the community shifted to an agricultural base. Irrigation changed the residents from sheep ranchers to orchardists. People were struggling to recover when along came World War II.
Early in the war years, the U. S. Army selected Pasco, across the river from Kennewick, for a new Army air base. A major shipping and warehouse facility was also built. Pasco couldn't handle the influx of people, so Richland and Kennewick provided housing. Many new businesses sprang up to support them as well. In the western part of the county, patriotic residents contributed enough money to build the new Prosser Memorial Hospital. But this boom turned out to be only the calm before the storm.
In 1942, the U.S. Army Corps of Engineers, Manhattan District, surveyed the northern part of the county for a secret government project. In 1943, the government ordered everyone living in the town sites of Hanford and White Bluffs to evacuate. Shortly thereafter, a huge government construction project began, known only as the Manhattan Project. Thousands of people moved to the Eastern Washington desert. No one knew what they were building, just that it would help the war effort. Only when they heard the news of the devastation caused by the atomic bomb dropped on Hiroshima and Nagasaki on August 6, 1945, did the workers know what they had built. "Our bomb clinched it!" read the Richland Villager.
After the war was over, everyone expected that the Hanford Engineer Works, named for the former town, would be shut down. It proved not to be the case. The Cold War demanded the nation develop its nuclear capability. Government contractors at Hanford developed the reduction-oxidation process, a new chemical separation process that saved scarce uranium. Two evaporators were built to reduce the amount of liquid in waste products so that it took up less space. Six new nuclear reactors and the plutonium-uranium extraction (PUREX) plant were completed. Other processes were developed to produce isotopes, especially cesium, strontium, and promethium. During this post-war boom, the small community of West Richland was born on the other side of the Yakima River. The town absorbed many of the new residents moving into the area. A new shopping complex was built in Uptown Richland. A huge trailer park was built in North Richland to help alleviate the housing shortage.
Other factors caused a boom in the area too. In the Plymouth area, the U.S. Army Corps of Engineers started building the McNary Dam on the Columbia River in 1947. The dam, dedicated in 1954, brought new waves of workers to the area and added more electricity to the power grid. The reservoir that formed behind it deepened and widened the river channel, providing improved navigation for barge and ship traffic.
The reservoir also covered up most of the land that was known as Hover. Displaced residents moved to Finley and students were absorbed into that school district. Unlike the residents who were forced to leave Hanford and White Bluffs, the residents of Hover were offered fair compensation for their land and received plenty of warning that they had to leave. Residents could also purchase any of the buildings on their property and move them.
Several new manufacturing businesses developed in the old Finley area (south of Kennewick) during the 1950s and 1960s. Several factors made the area desirable. Abundant cold water was available for industrial purposes. There was access to three transcontinental railroads, a well-developed electrical power grid, and a deep water shoreline on the Columbia. Allied Chemical built a plant in 1953 to produce chemicals for paper mills. California Spray Chemical Company built a fertilizer plant in 1959. In 1969, Collier Carbon and Chemical Company erected a storage and distribution center for different types of organic fertilizers. The firm also installed a large rail yard and dock to accommodate large shipments.
In 1966, Sandvik Special Metals opened its doors in the Finley area. Its initial purpose was to manufacture zirconium tubing for the nuclear industry. Later it expanded to titanium manufacturing, which it has fabricated into special lightweight, accurate, and strong shafts for golf clubs, mountain bikes, pool cues, tennis rackets, and racquetball rackets. Other industries that built in this area include Philips Pacific Chemical Co., Liquid Air Inc., Kerley Chemical, and the Gas Ice Corp.
In 1987, the U.S. Department of Energy signed what is called the Tri-Party Agreement, a 30-year plan to clean up the legacy of wartime nuclear and chemical waste. Deteriorating fuel rods would be moved from their precarious storage area near the Columbia River. Toxic chemicals will be pumped from leaky storage tanks into more permanent non-permeable storage tanks. New methods of cleaning up and neutralizing toxic waste spills will be studied for incorporation into all manner of industrial complexes.
In 1989, Washington State University expanded an existing facility in Richland to accommodate a full branch campus. Now it was possible for county residents to earn complete bachelor's degrees and master's degrees without leaving the area. The WSU Irrigated Agriculture and Research Extension Center, located 10 miles north of Prosser, is the world's largest irrigated experiment station.
In 1993, the Environmental Molecular Sciences Laboratory opened in north Richland. This new laboratory is part of Battle Northwest Laboratories. Richland continues to promote scientific operations and research.
Most of the county's court trials, jail space, and legal offices are located in Kennewick, since most of the county's population is in the southeast part of the county, but Prosser remains the county seat. The assessor's office and other important government functions are still conducted there. Prosser enjoys a prime location on a major river (the Yakima) and a highway interchange that invites tourists to come and enjoy its growing wine businesses. Columbia Crest, the state's largest winery, is located at Paterson on the Columbia River.
There have been many other little towns and train stations in the county, but most had vanished by the end of the twentieth century. In 2004, there were only five incorporated cities in the county: Richland, Kennewick, West Richland, Benton City, and Prosser. Kiona, Plymouth, and Paterson are unincorporated residential areas with few services. Finley and Hover are now nothing more than the names of school districts in Kennewick. Benton City and West Richland have more substantial populations but remain largely residential areas whose residents commute to Kennewick or Richland for shopping and entertainment.
According to the U.S. Census Bureau, the county has a total area of 1,760 square miles (4,559 km²), of which, 1,703 square miles (4,411 km²) of it is land and 57 square miles (148 km²) of it (3.24%) is water.
The area of south-central Washington occupied by Benton County has been known primarily as an agricultural hub since its settlement by white Americans. The rise of viticulture has had a profound impact on the agricultural and tourism industries over the past two decades, and has in many ways reshaped the reputation of the region.
Benton County is serviced by the Benton County Sheriff's Office.