Riverside State Park, State park in Nine Mile Falls, United States

Riverside State Park is a nature reserve stretching along two rivers near Spokane, with diverse landscapes ranging from steep valleys to broad plateaus. The terrain is shaped by multiple river sections that feature whitewater rapids, creating a dynamic natural environment.

The reserve was established in the 1930s by a work team that built bridges, trails, and roads while replanting forests across the land. This foundational work continues to shape the park's structure and accessibility today.

The Spokane House Interpretive Center in the park displays exhibits on the Spokane Indians, early pioneers, fur trappers and traders, and the nearby Spokane House fur trading post. The park's name comes from its riverside setting along the Spokane and Little Spokane rivers, not from a single river called Riverside.

The ranger station is at 9711 W. Charles Road in Nine Mile Falls. The Spokane River Centennial Trail runs 37 miles through the park, and the Little Spokane River Natural Area is reached from Waikiki Road. Campgrounds sit at Bowl and Pitcher, the equestrian area and Lake Spokane.

The park's 600-acre off-road vehicle area is one of several distinct zones, alongside an equestrian trail area and the Little Spokane River Natural Area. The Spokane House Interpretive Center covers the Spokane Indians, fur trappers and traders, and the nearby fur trading post. Camp Seven Mile, where CCC workers lived, later became a military base; Clark Gable trained there during World War II.