Forest Park is a public municipal park in the Tualatin Mountains west of downtown Portland, Oregon, United States. Stretching for more than on hillsides overlooking the Willamette River, it is one of the country's largest urban forest reserves. The park, a major component of a regional system of parks and trails, covers more than of mostly second-growth forest with a few patches of old growth. More than of recreational trails, including the Wildwood Trail segment of the city's 40-Mile Loop system, crisscross the park.
As early as the 1860s, civic leaders sought to create a natural preserve in the woods near Portland. Their efforts led to the creation of a municipal park commission that in 1903 hired the Olmsted Brothers landscape architectural firm to develop a plan for Portland's parks. Acquiring land through donations, transfers from Multnomah County, and delinquent tax foreclosures, the city eventually acted on a proposal by the City Club of Portland and combined parcels totaling about to create the reserve. Formally dedicated in 1948, it ranks 19th in size among parks within U.S. cities, according to the Trust for Public Land. The Trust for Public Land (TPL) lists the size of the park as , which is close to its original size of 1948. If the size claimed by the Portland Parks & Recreation Department in 2009 were used in the TPL listing, Forest Park would rank 17th.
More than 112 bird species and 62 mammal species frequent the park and its wide variety of trees and shade-loving plants. About of rain falls on the forest each year. Many small tributaries of the Willamette River flow northeast through the woods to pipes or culverts under U.S. Route 30 at the edge of the park. One of them, Balch Creek, has a resident trout population, and another, Miller Creek, supports sea-run species, including salmon.
Threats to the park include overuse, urban traffic, encroaching development, invasive flora, and lack of maintenance money. Occasional serious crimes and more frequent minor crimes occur in the park.
Geology and geography Solidified lava from Grande Ronde members of the Columbia River Basalt Group underlie Forest Park. About 16 million years ago during the Middle Miocene, the Columbia River ran through a lowland south of its modern channel. Eruptions from linear vents in eastern Oregon and Washington flowed down this channel through what later became the Willamette Valley. These flows, some of which reached the Pacific Ocean, recurred at intervals between 16.5 and 15.6 million years ago and covered almost . About eight separate Grande Ronde Basalt flows have been mapped in the Tualatin Mountains (West Hills), where they underlie the steepest slopes of Forest Park and form the columned rocks visible along Balch Creek Canyon and Northwest Cornell Road. The West Hills were later covered by wind-deposited silts that become unstable when saturated with water. Stream bank instability and siltation are common, and landslides deter urban development at higher elevations.
Roughly long, the park is less than wide near downtown Portland and about wide at its northwestern end. It extends along the West Hills from West Burnside Street near downtown Portland to where the Willamette River divides to flow around Sauvie Island. Covering most of the east face of the ridge above the Willamette River, it is bounded by West Burnside Street on the south, Northwest Skyline Boulevard on the west, Northwest Newberry Road on the north, and Northwest St. Helens Road (U.S. Route 30) on the east. Elevations above sea level vary from near U.S. Route 30 at the base of the ridge to about near the crest of the ridge along Northwest Skyline Boulevard.
In 2008 Forest Park ranked 19th in size among the largest city parks in the United States, according to The Trust for Public Land. The trust's list included state parks, national parks, county parks, regional parks, and national wildlife refuges, as well as municipally owned parks located within cities. Chugach State Park in Anchorage, Alaska, was in first place with .
Portland author Marcy Houle says that the park "captures the essence of what is natural and wild and beautiful about the Northwest... From this forest sanctuary, panoramic views of the city of Portland, the Willamette and Columbia rivers, and five major peaks of the Cascade Range ... can be seen through the tall fir trees. From its inception ..., Forest Park has been a refuge for both people and wildlife, and an integral part of the environment of Portland."
Ecology
Vegetation
Forest Park lies in the Coast Range ecoregion designated by the U.S. Environmental Protection Agency (EPA). In its natural state, the forest consists mainly of three tree species: Douglas-fir, western hemlock, and western red cedar. It also includes smaller numbers of grand fir, black cottonwood, red alder, bigleaf maple, madrone, and western yew. Much of the forest that existed there before 1850 was gone by 1940. The stage of regrowth in the forest depends on when it was last logged or burned.
In the mid-1990s, about 1% of the total vegetation in the park consisted of grasses, bracken, thistle, and fireweed in sections of the forest cleared two to five years earlier. Another 2% had reached the shrub stage, between three and thirty years old, with small trees dominated by such plants as thimbleberry, salmonberry, and blackberry. Forest areas 10 to 30 years old that contained tall alder and maple trees and smaller conifers accounted for about 20% of the park.
Larger areas were occupied by forests in which conifers had grown taller than the alders and maples. About 50% of Forest Park consists of these areas, which are between 30 and 80 years old and in which Douglas-firs have begun to dominate. Another 25% of the park contains forests dominated by middle-aged conifers, 80 to 250 years old. In these areas, red alders, which live for about 100 years, have begun to die, and the Douglas-firs, which can live for 750 years, attain heights up to about . Under the big trees are shade-tolerant trees such as western red cedar, western hemlock, and grand fir and smaller plants such as Oregon-grape, vine maple, and salal.
The last forest stage, old growth, is reached after 250 years and includes many snags, downed and dead trees, and fallen logs. Timber-cutting and fires reduced old growth in Forest Park to "almost nothing" by 1940, and most of the forest has not yet attained this stage. Patches exist near Macleay Park and further west near Germantown Road and Newton Road. The largest tree in Forest Park is a Douglas-fir near the Stone House, the remains of a former public restroom near Balch Creek. It is high, and the trunk is in circumference.
Among the prominent wildflowers are Hooker's fairy bells, vanilla leaf, evergreen violet, and trillium. Invasive species include English ivy, European holly, clematis, morning glory, and Himalayan blackberry. Citizen groups such as the No Ivy League. and The Forest Park Conservancy engage in projects to remove ivy, maintain trails, and plant native species.
Wildlife
Wildlife in Forest Park is strongly affected by contiguous tracts of nearby habitat that make the park accessible to birds and animals from the Tualatin River valley, the Oregon Coast Range, the Willamette River, Sauvie Island, the Columbia River, and the Vancouver, Washington, lowlands. Sixty-two mammal species, including the northern flying squirrel, black-tailed deer, creeping vole, bobcat, coyote, Mazama pocket gopher, little brown bat, Roosevelt elk, and Pacific jumping mouse frequent Forest Park. Blue grouse, great horned owl, hairy woodpecker, Bewick's wren, orange-crowned warbler, osprey, northern pygmy-owl, and hermit thrush are among the more than 112 species of birds that have been observed in the park. In Balch Creek Canyon adjacent to Forest Park, the Audubon Society of Portland maintains a wildlife sanctuary with more than of trails, a wildlife care center, and avian exhibits. Amphibian species frequenting the Audubon Society pond include rough-skinned newts, Pacific tree frogs, and salamanders.
Pressure from habitat loss, pollution, hunting, and urban development has reduced or eliminated the presence of wolves, bears, and wild cats and has led to increased numbers of weasels, raccoons, and other small predators. Invasive plant species such as English ivy have made the habitat simpler and less supportive of native insects and the salamanders and other amphibians that feed on them. Roads in the area severely hamper the movement of large animals. Multnomah County has designated Northwest Cornell Road and Northwest Germantown Road as "rural collector" streets, carrying traffic of less than 3,000 vehicles per day but more than streets designated as "local roads". Dogs allowed to run (illegally) off-leash in the park pose threats to birds, fish, and other wildlife.
Creeks About of rain falls on Forest Park each year. Many small creeks, only a few of which are named, flow northeast through the park from the ridge at the top of the West Hills to the base of the hills near U.S. Route 30. The five named streams from east to west are: Balch Creek, Rocking Chair Creek, Saltzman Creek, Doane Creek, and Miller Creek. Rocking Chair Creek is a tributary of Saltzman Creek. After leaving the park, the streams pass through culverts and other conduits before reaching the Willamette River. These conduits block fish migration to and from the Willamette River except on Miller Creek, where the conduits are short and have been modified to assist the fish.
Near the east end of the park, the free-flowing reaches of Balch Creek support a population of resident cutthroat trout. Near the west end, furthest from the city center, Miller Creek retains much of its historic nature and supports a greater diversity of aquatic organisms than other Forest Park streams. Biological field surveys of Miller Creek in 1990 noted sea-run cutthroat trout, coho salmon, and short-head cottid, as well as abundant macroinvertebrate species including stoneflies, mayflies, caddisflies, water striders, and crayfish.
History
Before settlers arrived, the land that became known as Forest Park was covered by a Douglas-fir forest. By 1851, its acreage had been divided into donation land claims filed by settlers with plans to clear the forest and build upon the property. After logging, the steep slopes and unstable silt loosened by heavy rains caused landslides that defeated construction plans, and claims were defaulted or donated to the city.
Civic leaders beginning with the Reverend Thomas Lamb Eliot, a minister who moved to Portland in 1867, sought to create a natural preserve in the woods that eventually became Forest Park. By 1899, Eliot's efforts led to the formation of the Municipal Park Commission of Portland, which in 1903 hired the highly regarded landscape architecture firm, the Olmsted Brothers of Brookline, Massachusetts, to study the city's park system and recommend a plan. John Charles Olmsted, the stepson of Frederick Law Olmsted, spent May 1903 in Portland. The Olmsted Report, received in December, emphasized creation of a system of parks and linking parkways that would take advantage of natural scenery. It proposed a formal square for Union Station, squares along the downtown waterfront, and parks in places later known as Forest Park, Sellwood Park, Mount Tabor Park, Rocky Butte, and Ross Island, as well as Terwilliger Parkway, the 40-Mile Loop, and other connecting parkways. Proposed parks for Swan Island, in the Willamette River, and other places in Portland did not develop. Others like Forest Park came into being only many years later.