Plaza is situated in a valley formed by Spangle Creek, located approximately 7 miles (11 km) north of Rosalia.

U.S. Route 195, a major north–south highway in the Palouse region, ran through the settlement until it was relocated to a bypass in 1974.

There are no services in Plaza, and the community itself is only a few square blocks in size, but the grain elevators in town make it a landmark for drivers on the highway.

Plaza was founded by Robert Patterson, a former Pony Express rider who had operated throughout Washington Territory.

He built a general store along the rail line that ran between Spokane and Colfax, and a small community of farmers and tradesmen cropped up around it.