The town of Beaver, Oregon does exist. It is located 20 miles south of Tillamook, OR, and 20 miles east of the Pacific Ocean. However, no scenes in this movie were filmed there.
Briefly features Return of the Tres, performed by Delinquent Habits - a song prominently featured in Double Take (2001), a movie Orlando Jones starred in prior to this film.
The scene where Chris Klein walks slowly into a biker bar, approaching Orlando Jones at a stainless steel bar, was shot at the Hotel Burnaby, 7610 Kingsway, Burnaby, British Columbia - a hotel since replaced by townhouses. Added to the 1953 hotel in 1960, the bar was largely original, down to the cinched terry cloth covers on the tables; however, to make it an "Oregon" bar, all Canadian beer signs were hidden during the shoot, with American beer signs temporarily installed. Notably, a large kitchenette room toward the back of the same hotel was used in the sequel to the film "My American Cousin," entitled "American Boyfriends," nearly two decades before "Say It Isn't So."