Rockport State Park, Ancient forest state park in Skagit County, US.

Rockport State Park is a 632-acre (256 ha) public recreation area at the foot of Sauk Mountain in Skagit County, Washington, north of the Skagit River. Nearly 600 acres (240 ha) are old-growth forest of cedars, Douglas firs, hemlocks, yews, alders and maples, with some Douglas firs reaching 75 m. Five miles of trails include the Evergreen Trail through the old growth and the Sauk Mountain Trail, reachable from Highway 20.

A timber company sold the land to Washington State in 1935, securing the ancient forest from logging operations. This transaction established the park and protected one of the last remaining untouched old-growth forests in the region.

A memorial marker in the park commemorates David Douglas, the Scottish botanist after whom the Douglas fir is named. The marker stands among the trees he described, some of which reach 75 metres in height.

Camping is closed indefinitely because of the risk from falling branches under the old trees. The Sauk Mountain Trail starts at the western edge of the park and is reached from Highway 20. The park lies north of the Skagit River, at the foot of Sauk Mountain.

The forest has never been logged commercially, creating a dark understory where sunlight barely penetrates the canopy. These shaded, moist conditions support the growth of rare mosses and ferns seldom seen elsewhere.