The park's geology features vertical basalt cliffs formed by ancient lava flows and subsequent erosion by the Columbia River.
Ainsworth serves as the eastern terminus for the Historic Columbia River Highway State Trail, a paved path built on the historic original highway route.
The location is located within a National Scenic Area designated to protect the unique geological and cultural landscape of the Gorge.
The park was designed to accommodate the heavy traffic of the historic highway, which was the first scenic road in the United States.
Ainsworth State Park is situated at the eastern end of the Columbia River Gorge, serving as a primary base for hikers exploring the waterfall-heavy trails of the region. The park features 40 full-hookup sites and 6 tent sites, catering primarily to overnight campers. A key feature is its immediate proximity to the Horsetail Falls trailhead and the Columbia River Gorge State Trail. The landscape is characterized by dense forest cover and high cliff walls typical of the gorge's volcanic geology. The park underwent significant repairs following the 2017 Eagle Creek Fire and now functions as a strategic access point for the surrounding trail network. It provides direct access to the Historic Columbia River Highway State Trail for pedestrians and cyclists.
The elevated sections of the Historic Columbia River Highway State Trail for sweeping gorge vistas.
Reserve campsites well in advance, as they fill up quickly during the peak spring and summer seasons.
Bring high-quality insect repellent if visiting during the warmer months, as the damp gorge environment attracts mosquitoes.
Pack a light rain shell even in summer, as the gorge creates microclimates with frequent mist.
Avoid parking outside of designated areas, as ticketing is strictly enforced by park rangers.
The park is typically closed during the winter months, reopening in late spring.
Practice 'Leave No Trace' principles; keep pets on a leash at all times.
