Forest Park

Forest Park is located on the northeast slope of Portland’s West Hills, the southernmost segment of the Tualatin Mountain Range. This narrow peninsula of land provides habitat connection all the way to the Oregon Coast Range. The park landscape is shaped by 30 miles of seasonal and perennial streams originating along the crest of the slope and draining east to the Willamette River. At nearly eight miles long and one mile wide, the park encompasses nearly 5,200 acres between four major arterial roads: NW Newberry Road, NW Skyline Blvd, W Burnside Road, and NW St. Helens Road.

The park’s steep terrain and silty soils support a diversity of plant species. Forest Park’s community of plants is called a Westside Lowlands Coniferous-Hardwood Forest and has a canopy dominated by Douglas fir, big leaf maple, grand fir, red alder, Western red cedar, and Western hemlock. Ferns, forbs, and shrubs are common native plant types in the understory, including Polystichum munitum (sword fern), Adiantum pedatum (maidenhair fern), Acer circinatum (vine maple), Mahonia nervosa (Oregon grape), and Trillium ovatum (trillium).

The forest canopy, creeks, and terrain provide habitat to over 100 species of birds, 50 species of mammals, and 400 species of invertebrates. The park also contains three fish-bearing streams with resident (non-migrating) trout: Balch Creek, Saltzman Creek, and Miller Creek. Salmonids have been documented in Forest Park only within Miller Creek, confirming that there is fish passage to the Willamette River.

Approximately half of the park is in good ecological health, supporting native species and proper watershed function. The other half is significantly impacted by the presence of invasive species and weedy trees, most prominently ivy, clematis, non-native blackberry, laurel, and holly. This has resulted from a history of disturbance caused by logging, wildfire, and the park’s exposure to residential and urban development along its perimeter.