Tryon Creek
Tryon Creek | |
---|---|
Socrates Hotchkiss Tryon, Sr., who settled nearby in 1850[2] | |
Location | |
Country | United States |
State | Oregon |
County | Multnomah and Clackamas |
Physical characteristics | |
Source | Tualatin Mountains (West Hills) |
• location | Portland, Multnomah County, Oregon |
• coordinates | 45°26′49″N 122°43′18″W / 45.44694°N 122.72167°W[1] |
• elevation | 641 ft (195 m)[3] |
Lake Oswego, Clackamas County, Oregon | |
• coordinates | 45°25′22″N 122°39′24″W / 45.42278°N 122.65667°W[1] |
• elevation | 10 ft (3.0 m)[1] |
Length | 4.85 mi (7.81 km)[4] |
Basin size | 6.5 sq mi (17 km2)[5] |
Discharge | |
• location | below the confluence with Nettle Creek, 1 mile (1.6 km) from the Tryon Creek mouth[6] |
• average | 8.72 cu ft/s (0.247 m3/s)[6] |
• minimum | 0.09 cu ft/s (0.0025 m3/s) |
• maximum | 1,210 cu ft/s (34 m3/s) |
Tryon Creek is a 4.85-mile (7.81 km) tributary of the
The bedrock under the watershed includes part of the last exotic terrane, a chain of seamounts, acquired by the North American Plate as it moved west during the Eocene. Known as the Waverly Hills Formation, it lies buried under ash and lava from later volcanic eruptions, sediments from flooding and erosion, and layers of wind-blown silt. Two dormant volcanoes from the Boring Lava Field are in the Tryon Creek watershed.
Named for mid-19th century settler,
Course
Tryon Creek begins slightly north of
Tryon Creek receives Falling Creek from the right at 4.16 miles (6.69 km) from the mouth. Quail and Burlingame creeks enter from the right shortly thereafter. At Marshall Park, the stream passes through a series of rock pools and steps known as the Marshall Cascade from RM 3.48 (RK 5.60) to RM 3.28 (RK 5.28). At the end of the Marshall Cascade, it receives Owl Creek. Arnold Creek, which is Tryon Creek's largest tributary, enters from the right 2.68 miles (4.31 km) from the mouth. Almost immediately, the creek enters a culvert, about 150 feet (46 m) long, that passes under Southwest Boones Ferry Road.[4][9][10][11]
Shortly thereafter, Tryon Creek enters the Tryon Creek State Natural Area. To the stream's right is the North Creek Trail. Soon the creek receives Fourth Avenue Creek from the left. At this point, the Fourth Avenue Trail runs parallel to the creek along the left bank. This trail soon merges with the Lewis and Clark Trail, which also runs parallel to the creek along the left bank. Then Tryon Creek passes under the High Bridge, the uppermost of five footbridges that span the main stem within the park. High Bridge carries the Middle Creek Trail as well as a linear horse trail connecting the park's North and South horse loops. Below this bridge, the creek flows for about 0.20 miles (0.32 km) before passing under the Beaver Bridge. In this stretch, the Middle Creek Trail parallels the stream along the right bank but crosses to the left bank at the bridge. Shortly thereafter, the creek passes under Obie's Bridge, which carries the Old Man Trail.[4][9][10][11]
Park Creek enters from the right at RM 1.80 (RK 2.90). Slightly below the confluence, the creek passes under the Red Fox Bridge, which carries the Red Fox Trail. Thereafter, the creek runs roughly parallel to the South Creek Trail, which is on the right for about 0.40 miles (0.64 km). The creek receives Red Fox Creek from the right and Palatine Hill Creek from the left, then flows out of Portland and Multnomah County and into the city of Lake Oswego and Clackamas County. The stream then passes under the Iron Mountain Bridge, which carries the Iron Mountain Trail. Just below the bridge, Nettle Creek enters from the right at 1.06 miles (1.71 km) from the mouth, and shortly thereafter the creek passes a United States Geological Survey (USGS) stream gauge, which is on the right. The creek leaves the Tryon Creek State Natural Area just before entering a 200-foot (61 m) culvert under Oregon Route 43 at RM 0.24 (RK 0.39) and soon thereafter a set of Union Pacific Railroad tracks. Below this, Tryon Creek forms the boundary between the city of Lake Oswego and Briarwood, an unincorporated Clackamas County community, which is to the left. The Tryon Creek Wastewater Treatment Plant is on the right during this last stretch before the creek enters the Willamette River about 20 miles (32 km) upstream from its confluence with the Columbia River.[4][9][10][11]
Discharge
Since 2002, the USGS has monitored the flow of Tryon Creek at a station 1 mile (1.6 km) from the mouth. The average flow between 2002 and 2011 was 8.72 cubic feet per second (0.25 m3/s). This is from a drainage area of 6.28 square miles (16.27 km2), about 97 percent of the total Tryon Creek watershed. The maximum flow recorded during this period was 1,210 cubic feet per second (34 m3/s) on December 9, 2010. The minimum was 0.09 cubic feet per second (0.0025 m3/s) on September 4, 5, and 12, 2002.[6]
Geology
One hundred and fifty million years ago, Oregon did not exist.[12] Not until plate tectonics separated North America from Europe and North Africa and pushed it westward did the continent acquire, bit by bit, what became the Pacific Northwest. Over many millions of years, the continent collided with and incorporated islands, reefs, and other exotic terranes.[12] Part of the last major exotic terrane acquired by the North American Plate during the Eocene lies under the Tryon Creek watershed. The terrane consisted of a chain of seamounts that by 34 million years ago was being uplifted to become the Oregon Coast Range and the Tualatin Mountains (West Hills).[13] The easternmost exposure of the basalts of this terrane is in Waverly Heights, near Milwaukie, across the Willamette River from Tryon Creek, and this formation underlies most of Tryon Creek State Park.[13]
Between 15 and 16 million years ago, in the
Starting about 3 million years ago and continuing at least through the late Pleistocene, extensional faulting of the Earth's crust led to eruption of small volcanoes in the Boring volcanic field. This field extended roughly from Portland and Tualatin on the west to Battle Ground, Washington, on the north to Sandy and Boring on the east.[16] Two of these volcanoes, Mount Sylvania and Cook's Butte, are in the Tryon Creek watershed. The Mount Sylvania eruptions included ash plumes and lava flows that covered some of the Waverly Heights Formation and Columbia River basalts.[15]
About 15,000 years ago, cataclysmic
Watershed
The Tryon Creek watershed covers about 4,100 acres (1,700 ha) or 6.5 square miles (17 km2). Of this, about 80 percent is within the Portland city limits, and the remaining 20 percent is split among the jurisdictions of the city of Lake Oswego, and the counties of Multnomah and Clackamas. These four overlap with the jurisdiction of the State of Oregon, which owns the natural area. Watersheds that border the Tryon Creek watershed are Fanno Creek to the west and northwest, Stephens Creek to the north, the Willamette River to the east and Oswego Lake to the south. More than 70 miles (110 km) of surface streets, including parts of Interstate 5, Oregon Route 99W, Oregon Route 43, Boones Ferry Road, Taylors Ferry Road, and Terwilliger Boulevard, run through the watershed.[8]
About 35 inches (890 mm) of precipitation, almost entirely rain, fall on the watershed each year. Summers are dry, and most of the precipitation occurs between October and May.[19] Elevations within the drainage basin vary from Mount Sylvania, which rises to 970 feet (300 m) above sea level in the West Hills, to 10 feet (3.0 m) where the creek enters the Willamette River.[19] Between 60 and 75 percent of the slopes in the watershed exceed a 30-percent grade and are especially steep near the headwaters.[19] Impervious surfaces cover about 24 percent of the basin.[19] These surfaces and the relatively impermeable silt and clay soils that underlie the area contribute to rapid runoff and low baseflows in the creek and its tributaries. The total length of surface streams in the drainage basin is about 27 miles (43 km), while another 3 miles (5 km) run through culverts or pipes.[19] Although major flooding in 1996 caused landslides and severe damage to stream beds and banks along Tryon Creek and its tributaries, it caused no significant property damage in the watershed.[20]
In 2000, the population of the Tryon Creek watershed within Portland was about 18,000. In 2005, Portland's Bureau of Environmental Services (BES) described land-use
Tributaries
The major smaller streams in the Tryon Creek watershed are Arnold Creek and Falling Creek. The larger of the two, Arnold Creek, has a watershed of roughly 1.2 square miles (3.1 km2) or 18 percent of the 6.5-square-mile (17 km2) total, while Falling Creek's watershed covers 0.4 square miles (1.0 km2) or 6 percent of the total.[8] The seven named tributaries from mouth to source are Nettle, Palatine Hill, Red Fox, Park, Fourth Avenue, Arnold, and Falling creeks.[4][9][10][11]
Water quality
Oregon Department of Environmental Quality (DEQ) developed the Oregon Water Quality Index (OWQI) in the 1970s to rate general water quality at different locations. Scores can vary from 10 (worst) to 100 (ideal). Portland's Bureau of Environmental Services (BES) incorporated the OWQI into its monitoring of Tryon Creek in 1997. As of 2004, the overall OWQI score for Tryon Creek was 74 or "poor"; this was slightly better than nearby Fanno Creek at 67.[22] The State of Oregon listed Tryon Creek as "water-quality limited" in 1998 because water temperatures on the lower 5 miles (8 km) of the main stem as well as on Nettle, Arnold, and Falling creeks exceeded the upper limit for protecting salmonid fish rearing and migratory fish passage during the summer.[23]
BES monitors water quality at three Tryon Creek sites. Two are near I-5 and Barbur Boulevard in the upper watershed, and the third is at Southwest Boones Ferry Road, about 2.7 miles (4.3 km) from the mouth. BES looks at several indicators such as dissolved oxygen, nutrients, and total suspended solids. Diffuse pollution from nonpoint sources enters the creek from its urban surroundings. Point sources of pollution in the creek include two major upper-watershed stormwater outfalls draining 368 acres (149 ha) of the upper watershed and contributing about half of the creek's total suspended solids. As of 2004, the only water-quality indicator in the watershed that failed to meet minimal standards was the water temperature.[24]
Annual report card
In 2015, BES began issuing annual "report cards" for watersheds or fractions thereof that lie within the city.
History
In 1850,
Logging resumed in 1912 in the north part of the canyon, where The Boone's Ferry Wood and Tie Company had a site near what became Alfred Street. A sawmill and
Local efforts began in the 1950s to establish a park along the creek, In 1969, the government of Multnomah County bought 45 acres (18 ha) to start a large regional park and sought citizen assistance with the project. This led to formation of Friends of Tryon Creek Park, which raised funds, helped arrange land deals, worked on problems of jurisdiction in a two-county, two-city park, and sought help from the state. In 1970, Oregon Governor Tom McCall announced the formation of Tryon Creek State Park.[33]
Over the next few years, the state bought more than 600 acres (240 ha) of land for nearly $3 million, including federal
Vegetation and wildlife
Riparian zones and floodplains are relatively intact along the lower reaches of the main stem in the state natural area, fairly intact in Marshall Park, and marginal in the upper reaches surrounded by homes. Arnold Creek has riparian corridors wider than 100 feet (30 m) in good condition, while Falling Creek's riparian zones, surrounded by homes, are in poor condition. Damaged zones from which native vegetation has been removed lead to erosion, stream bank failure, sedimentation, lack of shading, and higher stream temperatures.[34]
Tryon Creek is among the few streams in the Portland metropolitan area with a run of steelhead Trout,[37] and coho salmon have been recorded spawning in the creek.[35] Surveys by the Oregon Department of Fish and Wildlife in 2002 found coho, chinook salmon, steelhead, and coastal cutthroat trout in different parts of the creek at different times of the year. None was present in large number. Cutthroat trout had the biggest population, estimated at 53 individual fish during the spring of 2002.[34] Signal crayfish have also been found in significant numbers.[38] Water striders, which are invertebrates that can walk on water, are common in the pools of Tryon Creek.[35] More than 60 species of birds, including Cooper's hawks, great blue herons, kingfishers, towhees, waxwings, and wrens frequent the area. Some of the resident mammals are bats, coyotes, moles, rabbits, skunks, and squirrels, while frogs, salamanders, snakes, and turtles also do well in the watershed.[34]
Parks
Parks in the Tryon Creek watershed include Tryon Creek State Natural Area, Oregon's only metropolitan state park.[37] At about 630 acres (250 ha), the natural area is much larger than the watershed's other parks.[8]
The state park includes a 3-mile (5 km) bicycle path that runs along Terwilliger Boulevard on the east edge of the park as part of the Portland metropolitan area's system of greenway trails known as the 40-Mile Loop. Equestrians can ride through the woods on horse trails totaling about 5 miles (8 km). Hikers can use the bike path, horse trails, and about 8 miles (13 km) of hiking trails. A paved loop trail of about 0.35-mile (0.56 km), furnished with drinking fountains and interpretive signs, can accommodate wheelchairs. A park building called the Nature Center houses a gift shop, a large classroom, space for educational exhibits, and a play area for small children.[39]
Tryon Creek, which flows through the middle of the state park, also runs through Marshall Park, a modified natural area of about 26 acres (11 ha) in a canyon in the hills northwest of Mount Sylvania. It features hiking trails, a playground, picnic tables, a waterfall, and a stone bridge over the creek.[40] Other parks in the watershed include West Portland Park, a natural area of about 15 acres (6 ha),[41] Foley-Balmer Natural Area, and Maricara Park, a natural area of about 17 acres (7 ha).[42] Metro plans to acquire additional land along the creek to add to the parks.[21]
See also
References
- ^ a b c "Tryon Creek". Geographic Names Information System. United States Geological Survey, United States Department of the Interior. November 28, 1980. Retrieved May 3, 2009.
- ^ McArthur & McArthur 2003, pp. 970–71.
- ^ Source elevation derived from Google Earth search using GNIS source coordinates.
- ^ a b c d e f Portland Bureau of Environmental Services 2005, pp. 1–7, Chapter 10.
- ^ Portland Bureau of Environmental Services 2005, p. 1, Chapter 2.
- ^ a b c United States Geological Survey. "Water-Data Report 2011: USGS 14211315 Tryon Creek Near Lake Oswego, OR" (PDF). Retrieved November 23, 2012.
- ^ Although other sources give the creek's length as 7 miles (11 km), Chapter 10 of Fanno and Tryon Creeks Watershed Management Plan by the Portland Bureau of Environmental Services gives a precise length of 4.85 miles (7.81 km). The plan describes inflow above that point as a "headwaters complex" that "includes all small upper tributaries above RM 4.85." By convention, stream lengths do not include tributary lengths.
- ^ a b c d Portland Bureau of Environmental Services 2005, pp. 1–5, Chapter 2.
- ^ ISBN 978-1-897152-94-2.
- ^ a b c d e United States Geological Survey. "United States Geological Survey Topographic Map: Lake Oswego, Oregon, quadrant". TopoQuest. Retrieved May 10, 2009.
- ^ a b c d e Tryon Creek Trail Map (Map) (April 2008 ed.). Oregon Parks and Recreation Department.
- ^ a b Bishop 2003, pp. 13–14.
- ^ a b Bishop 2003, pp. 101–02.
- ^ a b Bishop 2003, pp. 144–48.
- ^ a b c "Tryon Creek Watershed Atlas, Part Two: A Profile of the Tryon Creek Watershed". Portland State University. 1994–95. Archived from the original on July 20, 2006. Retrieved June 8, 2009.
- ^ Bishop 2003, pp. 192–93.
- ^ Bishop 2003, pp. 226–29.
- ^ "Lake Oswego Surface Water Management Plan, Chapter 3: Study Area Characteristics" (PDF). City of Lake Oswego. 1992. p. 2. Archived from the original (PDF) on February 26, 2012. Retrieved June 8, 2009.
- ^ a b c d e Portland Bureau of Environmental Services 2005, pp. 5–9, Chapter 2.
- ^ Portland Bureau of Environmental Services 2005, pp. 16–17, Chapter 2.
- ^ a b "Tryon Creek Linkages". Metro Regional Government. 2009. Archived from the original on April 7, 2014. Retrieved September 23, 2009.
- ^ Portland Bureau of Environmental Services 2005, pp. 11–13, Chapter 6.
- ^ Portland Bureau of Environmental Services 2005, pp. 15–16, Chapter 6.
- ^ Portland Bureau of Environmental Services 2005, pp. 2–7, Chapter 6.
- ^ Portland Bureau of Environmental Services (2015). "About Watershed Report Cards". City of Portland. Retrieved May 10, 2015.
- ^ Portland Bureau of Environmental Services (2015). "Report Cards". City of Portland. Retrieved May 10, 2015.
- ^ Portland Bureau of Environmental Services (2015). "What We Measure". City of Portland. Retrieved May 10, 2015.
- ^ Portland Bureau of Environmental Services (2015). "Tryon Creek Report Card". City of Portland. Retrieved May 11, 2015.
- ^ "Lost Landmarks: Other Neighborhoods: Tryon House" (PDF). Oswego Heritage Council. Archived from the original (PDF) on March 20, 2009. Retrieved September 22, 2009.
- ^ McArthur & McArthur 2003, pp. 203–04, 684.
- ^ a b c d Taylor, Barbara (1999). "Indian Use" (PDF). Salmon and Steelhead Runs and Related Events of the Clackamas River Basin: A Historical Perspective. Portland General Electric. Archived from the original (PDF) on March 12, 2006. Retrieved July 4, 2009.
- ^ a b "Multnomah Indians". Lewis and Clark Interactive Journey Log. National Geographic. 2008. Archived from the original on February 17, 2015. Retrieved July 4, 2009.
- ^ a b c d "History of the Park". Friends of Tryon Creek State Park. Archived from the original on August 17, 2007. Retrieved April 6, 2009.
- ^ a b c d Portland Bureau of Environmental Services 2005, pp. 13–16, Chapter 2.
- ^ a b c Houck & Cody 2000, pp. 48–50.
- ^ Portland Bureau of Environmental Services 2005, pp. 13–16, Chapter2.
- ^ a b "Tryon Creek State Natural Area". Oregon Parks and Recreation Department. Retrieved April 6, 2009.
- ISSN 2168-0620. Retrieved December 30, 2022.
- ^ Weist, Ellison G. (October 23, 2007). "Tryon Creek Trails Welcome Hooves, Wheels". Portland Tribune. Pamplin Media Group.
- ^ "Marshall Park". Portland Parks and Recreation. 2009. Retrieved September 15, 2009.
- ^ "West Portland Park Natural Area". Portland Parks and Recreation. 2009. Retrieved September 15, 2009.
- ^ "Maricara Natural Area". Portland Parks and Recreation. 2009. Retrieved September 15, 2009.
Sources
- Bishop, Ellen Morris (2003). In Search of Ancient Oregon: A Geological and Natural History. Portland, Oregon: Timber Press. ISBN 978-0-88192-789-4.
- Houck, Mike; Cody, M. J., eds. (2000). Wild in the City: A Guide to Portland's Natural Areas. Portland: Oregon Historical Society Press. ISBN 0-87595-273-9.
- McArthur, Lewis A.; McArthur, Lewis L. (2003). ISBN 0-87595-277-1.
- Portland Bureau of Environmental Services (2005). "Fanno and Tryon Creeks Watershed Management Plan" (PDF). City of Portland. Archived from the original on May 6, 2015. Retrieved May 8, 2009.
External links
- Friends of Arnold Creek
- Friends of Marshall and Maricara Parks
- Friends of Tryon Creek State Park
- Tryon Creek Watershed Council