The series traces its origins to the Pacific Coast Late Model Division, founded in 1954 to provide drivers from the western United States with a competitive outlet closer to home at a time when stock car racing was largely centered in the Southeast. Nine races were held in the inaugural season, many of them in California at venues in Oakland, San Diego, San Mateo, and Gardena. The first series championship was won by Lloyd Dane driving a 1953 Hudson Hornet.
Over subsequent decades the series operated under several names — Grand National West Series, Winston West Series, NASCAR AutoZone West Series, and NASCAR Camping World West Series — before K&N Engineering assumed title sponsorship in 2010, giving the series the K&N Pro Series West name it carried until the ARCA transition.
While primarily a domestic series, the K&N Pro Series West expanded internationally on several occasions. In 1988 the series traveled to Australia for an exhibition race, and from 1996 to 1998 it visited Japan. In 1999 the series made history when the season finale was held at Twin Ring Motegi in Japan, becoming the first NASCAR points-paying race held outside North America.
In 2003, NASCAR consolidated the Busch North Series into the West Series, merging the two regional structures and producing the format that would continue through the K&N era. Races took place at oval tracks ranging from short quarter-mile layouts to tracks approaching one mile, with the series returning to dirt racing in 2018 after the last dirt race had been held in 1979.
The K&N Pro Series West shared its technical package with the East Series following the unification of rules in 2003. Cars ran a V8 pushrod engine of 358 cubic inches producing approximately 650 horsepower, paired with a four-speed manual transmission and running on a wheelbase of either 105 or 110 inches. Teams could build their own engines to NASCAR specifications or purchase a spec engine using NASCAR-approved components. From 2015, composite bodies produced by Five Star Race Car Bodies became the standard, replacing older steel bodywork and reducing fabrication costs.
Jack McCoy holds the all-time career victories record in the series with 54 wins, followed by Ray Elder with 47. Elder, however, earned the most championships with six titles. Bill Schmitt and Roy Smith each claimed four championships. Across its full history, 110 different drivers scored victories in the series.
Several drivers who later reached NASCAR's highest levels competed in the series during their careers, including Ryan Blaney, Kevin Harvick, Brendan Gaughan, Derrike Cope, Chad Little, and David Gilliland.
In December 2019, NASCAR announced Camping World as the new title sponsor for both Grand National regional series. The following year, in 2020, the K&N Pro Series West was absorbed into the newly branded ARCA Menards Series West following the formal merger between NASCAR and ARCA's regional structures. The ARCA Menards Series West continues to race across the same western territories, serving the same developmental function the series has carried since its origins in 1954.
The lineage of the NASCAR K&N Pro Series West makes it one of the foundational pillars of American regional stock car racing, predating even NASCAR's own fully established Cup circuit by several years in the western United States. Its record of international races, its long-tenured champions, and its role launching drivers toward NASCAR's national series give it a historical depth uncommon among regional championships. The ARCA Menards Series West is its direct successor and living continuation.