Cascadia State Park, State park in western Oregon, United States.

Cascadia County Park (formerly Cascadia State Park) lies along the South Santiam River at Cascadia, 14 miles east of Sweet Home on U.S. Highway 20. It has a day-use area, campsites, a one-mile Soda Creek Falls Trail to 150-foot Lower Soda Creek Falls, and a 0.75-mile loop River Trail down to the river. Douglas-fir, cedar and hemlock shade ferns, mosses and wildflowers such as trillium and camas.

Molalla and Kalapuya groups fished, hunted and gathered huckleberries at this site before settlers arrived. Settlers later cut a wagon bypass here, and in 1896 George Geisendorfer opened a resort with a hotel, tennis courts, a croquet course, a garden and a bowling alley, promoting Soda Creek's mineral spring water for its "curative powers". The hotel burned, Oregon bought the land in 1940, and in September 2022 the park passed to Linn County.

Molalla and Kalapuya groups came to this site to harvest huckleberries and to fish and hunt. Cascadia Cave nearby holds about 8,000-year-old petroglyphs, described as the largest concentration of rock engravings in western Oregon.

The park offers over 20 camping sites during the warmer season, with some available on a first-come-first-served basis and others requiring advance booking. Access is convenient from Highway 20, making it straightforward to find and reach.

Carved wagon ruts remain visible near Soda Creek, marking a route that early settlers created to bypass difficult terrain with horse-drawn carts. These grooves show how the land was actually used and traveled by people over time.