The Tri-Cities are three closely linked cities (Kennewick, Pasco, and Richland) at the confluence of the Yakima, Snake, and Columbia Rivers in the U.S. state of Washington. Located in the Columbia Basin of Eastern Washington, the cities border one another, making the Tri-Cities seem like one uninterrupted mid-sized city. The three cities function as the center of the Tri-Cities metropolitan area, which consists of Benton and Franklin counties. The Tri-Cities urban area includes the city of West Richland, the census-designated places (CDP) of West Pasco and Finley, as well as the CDP of Burbank, despite the latter being located in Walla Walla County.
The official 2023 estimate of the Tri-Cities MSA population is 314,253, a more than 24% increase from 2010, while the combined population of the three principal cities themselves was 228,482 according to 2023 estimates from the United States Census Bureau.
Tri-Cities Airport is located in Pasco and provides the region with commercial and private air service. Pasco is the seat of Franklin County, while the other two cities are located in Benton County. In 2010, Kiplinger rated the Tri-Cities among the Top 10 best places to raise a family, and CNN/Money ranked the Tri-Cities one of the top 10 best bets for gains in housing value, due to its relatively stable economic conditions since the early 2000s.
Area history
Founding
thumb|left|220px|Central Richland as seen from [[Badger Mountain (Benton County, Washington)|Badger Mountain]]
Pasco was the first of the Tri-Cities to be incorporated, in 1891. Kennewick was incorporated in 1904, and Richland followed in 1910. West Richland—a suburb of Richland, as well as the fourth largest city in the metropolitan area—was founded by dissatisfied residents of Richland, who wished to be home owners rather than renters of government-owned houses, after the arrival of Hanford. Despite attempts by Richland to annex the community, they remained separate and eventually became incorporated in 1955.
Early history
Pasco was the largest city in the Tri-Cities, mostly due to its railroad station. It also had the most land for easy irrigation and farming and was still the largest up until the founding of Hanford near Richland.
Farming was the basis of virtually every sector of the economy in the early years. Indeed, the area remained mostly rural well into the 1940s. It did not have a daily newspaper or radio station until the mid-1940s. Even today, agriculture is a big part of the Tri-Cities, Pasco in particular.
1940s–1970s
After the founding of the Hanford Site in 1943 as part of the Manhattan Project, Richland became the largest city of the three overnight. Richland's Columbia High School adopted "Bombers" as its mascot (complete with mushroom cloud logo). In 1970, Kamiakin High School (in the neighboring city of Kennewick) was founded in response to the continued influx of people. The economy continued to grow, but not without some turbulence. Every time the Hanford facilities experienced reduced funding, thousands of people would suddenly become jobless. During this time, other employers slowly made their way into the area, but they too would often be forced to cut jobs in the bad times. Since the 1970s, Kennewick has had the greatest population of the three cities. The Columbia Center Mall opened in 1969 on land newly incorporated into Kennewick, drawing growth to western Kennewick and south Richland.
1980s–1990s
thumb|right|284px|The Environmental Molecular Science Laboratory at [[Pacific Northwest National Laboratory, a major national laboratory in Richland]]
Completion of the Interstate 182 Bridge in 1984 made Pasco much more accessible, fueling the growth of that city. With the end of the Cold War, many in the area feared a shutdown of Hanford, followed by the Tri-Cities quickly becoming a ghost town. These fears were allayed after the United States Department of Energy switched the facility's purpose from the creation of nuclear weapons to the effective sealing and disposal of radioactive waste. During the 1990s, several major corporations entered the Tri-Cities, which helped to begin diversifying the economy apart from the Hanford sector. In 1995, a sixth public high school, Southridge High, was founded in south Kennewick.
2000s–present
The 2000s saw continued rapid growth as the Hanford site hired hundreds of workers to help with the cleanup effort. Additionally, the Tri-Cities saw a large influx of retirees from various areas of the Northwest. During this time, and the corresponding nationwide housing boom, all three cities flourished and grew significantly. Pasco became the fastest growing city in Washington (in terms of both percent increase and number of new residents). In 2005, the Census Bureau reported that Pasco's population had surpassed Richland's for the first time since pre-Hanford days. Fueled by the boom, Chiawana High School was founded, and by 2019 had become the largest high school in the entire state.
Despite the economic recession of the late 2000s, the Tri-Cities area continued to maintain steady growth and a stable economic climate due in part to the American Recovery and Reinvestment Act of 2009 which directed funding and jobs to the Hanford site and its various cleanup efforts.
Climate and geography
thumb|upright|The view of [[Rattlesnake Mountain (Benton County, Washington)|Rattlesnake Mountain, a windswept and treeless ridge 1,060 meters high, from the Horn Rapids Golf Course in Richland.]]The Tri-Cities are in a semi-arid climate, receiving an average of of precipitation every year. Winds periodically exceed when Chinook wind conditions exist. While there are an average 225 clear days every year, these are mainly between April 1 and November 1. Temperatures range from as low as in the winter (record low in December 1919) to as high as in the summer, and Richland reached during the 2021 Western North America heat wave. The region receives a yearly average of seven inches of snow but has received as much as 50 inches. Due to the semi-arid climate and subsequent large amounts of sand, a perpetual annoyance to residents is the amount of dust blown about by the frequent winds. Thanks to the aforementioned rivers, a large amount of cheap irrigation is available.
Washington is the most northwest of the lower 48 states—consequently, the area is in the Pacific Standard Time Zone. The Tri-Cities makes up the largest metropolitan area in the southeastern quadrant of Washington. The large Cascade Mountain Range to the west contributes to the semi-arid climate, which is far drier than the famously wet western side of the state. See rain shadow for more information on this phenomenon. The region's climate results in a shrub-steppe ecosystem which has 18 endemic plant species.