Onalaska is an unincorporated community and census-designated place (CDP) in Lewis County, Washington, United States.

[5] Onalaska was built around the inland mill established by the Carlisle Lumber Company in 1909,[6] with actual production commencing in 1914.

[7] During the Great Depression, with issues regarding falling timber prices and production, along with along with increased unionization efforts, the Carlisle family closed the facility.

[7] The company's surviving 225-foot smokestack near Carlisle Lake was built between 1918[7] and 1920, and is the last trace of one of the most successful mid-sized sawmills in Washington state.

Because of their experience in the mill, the local Japanese Americans were forced to relocate to Camp Tulelake in California to help with its construction, Kucera writes.

[10][11] In 2014, Governor Jay Inslee awarded $20,000 to Onalaska Wood Energy during his Climate Tour that year, and praised the company as “one of the leaders in biofuel technology.” By 2020, the company had left 100,000 gallons of hazardous waste and in 2021 the EPA started an emergency $0.9 million cleanup, shipping the waste by truck and railroad to Idaho and Utah.

Notable highlights of the event include an apple pie contest, a parade, farm tours, a community-wide church service, various cuisine options, high school alumni sporting competitions, canoe and kayak races, and a "royal court" bingo tournament.

The Onalaska Alliance is usually recognized as a major community leader, running the Apple Harvest Festival, maintaining Carlisle Lake, and cooperating with the school district and local businesses to better the town.

Onalaska is recognized as being majority Republican and conservative, similar in respects to other rural populations within Lewis County.

In 2023, the students released a combined 135,000 coho and steelhead hatchlings above a dam on Carlisle Lake into Gheer Creek.

[19] Onalaska is home to the Ed Herold Observatory, named after an amateur astronomer who raised the funds for the construction.