Benton SWCD Zones
Benton SWCD Zones

Benton County Geography and Soil

Benton County, Oregon is about 40 miles southwest of the capital city of Salem and about 45 miles northwest of the city of Eugene. Several rivers and numerous streams flow through Benton County. Its eastern border is the Willamette River, and Marys River watershed lies mostly within the boundaries of the County. Other rivers located partially within Benton County include The Long Tom, The Luckiamute, and The Alsea. The Alsea Basin is geographically separated from the rest of the county by the Coast Range. Benton County is home to Marys Peak, the tallest mountain in the Coast Range. 

Approximately 15,000 years ago the great ice dam of Missoula Lake thawed and refroze repeatedly causing 2,000 years of cataclysmic floods throughout what is now known as the Columbia River Gorge and the Willamette Valley. Those flooding events deposited rich sediments, making the Willamette Valley the most fertile and productive area in Oregon.

Marys Peak Sunset
Sunset view from Marys Peak.

Benton County

Present-day Benton County is located on the traditional lands of the Kalapuya tribes, who have lived here and cared for the area for thousands of years.

In 1847, Benton County was created from Polk County by an act of the Provisional Government of Oregon. It is one of seven counties in the United States to be named after Senator Thomas Hart Benton of Missouri, a longtime advocate of the development of the Oregon Territory. At the time of its inception, Benton County’s boundaries began at the intersection of Polk County and the Willamette River, ran as far south as the California border and as far west as the Pacific Ocean. Later, portions of Benton County were taken to form Coos, Curry, Douglas, Jackson, Josephine, Lane and Lincoln Counties, leaving it in its present form with 679 square miles of land area. In Benton County there are five incorporated cities (Corvallis, Philomath, Monroe, Adair Village and North Albany) and five officially designated unincorporated communities (Alsea, Wren, Alpine, Bellfountain and Greenberry).

Drawing of Corvallis from Cemetery Hill circa 1885 by JT Picket, courtesy Benton Co Historical Museum
Drawing of Corvallis from Cemetery Hill circa 1885 by JT Picket, courtesy Benton Co Historical Museum

History Timeline

Want to learn more about the area known as Benton County? Scroll through history to learn about Benton County’s agriculture and the events that have helped shaped the work of Benton Soil and Water Conservation District.

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Can information from the soil explain why some prairie restoration efforts are more successful than others? In 2016, the Prairie Soils for Sustainable Restoration project set out to find the answer, thanks to funding from Oregon Natural Resources Conservation Service.

Lessons with George Ice
Teresa Matteson | February 19, 2021

Diverse natural landscapes managed by landowners who understand and appreciate the importance of ecosystem services are fundamental to what makes Benton County a mighty fine place to live and work. One such landowner is George Ice, past BSWCD Chair. For 35 years, George worked as a research forest hydrologist with the National Council for Air

Conservation Neighbors: The Mellenthins
Laura Brown | December 29, 2020

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