Skip to main content

Basalt Creek Parkway Extension (Grahams Ferry Road to Boones Ferry Road)

This project will extend Basalt Creek Parkway from Grahams Ferry Road to Boones Ferry Road.

We are designing the Basalt Creek Parkway Extension between Grahams Ferry and Boones Ferry roads. 

Both 124th Avenue/Basalt Creek Parkway opened in 2017, linking Tualatin-Sherwood and Grahams Ferry roads. That was the first piece of a planned interconnected transportation network to support future development in the 850-acre Basalt Creek Planning Area. Planning for this area is a cooperative effort among the cities of Tualatin and Wilsonville and Washington County.  

Both the Basalt Creek Parkway and the Basalt Creek Parkway Extension are key elements of the Basalt Creek Transportation Refinement Plan.

The Basalt Creek Parkway Extension will have two lanes in each direction with multiuse (bicycle and pedestrian) paths and streetlights on both sides. A bridge will span Tapman Creek and adjacent wetlands. A new traffic signal will be installed where Basalt Creek Parkway connects with Boones Ferry Road. The street increases transportation system capacity to meet freight and commuter needs.


The Basalt Creek area currently lacks connected transportation facilities needed to support economic and urban-level development. The cities of Tualatin and Wilsonville and Washington County approved projects to be constructed over time. These include the extension of 124th Avenue and Basalt Creek Parkway to connect Tualatin-Sherwood and Boones Ferry roads.

The Basalt Creek Parkway Extension is an important piece of the interconnected transportation network needed to serve over 1,700 acres designated for industrial development in the cities of Tualatin, Wilsonville and Sherwood. The area is expected to create up to 14,000 jobs. The cities and county continue working together to implement the plans for this significant employment area.

Design start: Winter 2020
Design finish (expected): Spring 2025
Construction: Dependent on funding

Sign up to receive project updates by email 


3/6/2024: The county is reevaluating potential transportation project construction dates due to funding constraints and rapidly increasing costs. This process is expected to take several months.


Cost: $31 million (2019 estimate)

Funding amount: $6 million

Funding sources:



Biological Resources Report Summary 

No plant or animal species protected under the Endangered Species Act were found in the project area. In-water work will be restricted to July 15 - October 30 to limit impacts to fish. We are required to mitigate any impacts to wetlands and waters. We will replace trees and shrubs removed during construction with at least as many plants of native species. We will add about 3 acres of native seeds next to the roadway. 

The project area has many invasive species. We have been advised to clean plant material from equipment and limit the amount of land disturbed to reduce the spread. About four acres of treatment for weed control is expected.
Full biological resources report

Endangered Species Act Determination of No Effect

No state or federally listed endangered species or critical habitats were found in the area of potential impact for the Basalt Creek Parkway Extension project.
Determination of No Effect memo

Noise Report Summary 

This report looks at the noise impacts expected from the road extension. We use this to determine if it is feasible and reasonable to build sound walls. We use Oregon Department of Transportation guidelines. A reasonable cost per property owner is less than $25,000. 

On the north side of the proposed road sound walls would cost about $267,000 per property owner. On the south side of the road it would cost $114,000 per property owner. The cost of sound walls is too high to be reasonable. Sound walls are not recommended on this project.
Full noise report

Wetland Delineation Report

The Department of State Lands is reviewing the wetlands delineation report for the Basalt Creek Parkway Extension project.
Wetland delineation report

Prior events and comment opportunities

Open House: Feb. 25-March 13, 2022

Update: February 2021

Update: October 2020

Basalt Creek Road Extension concept art
Basalt Creek Road Extension Bridge concept art (aerial view)
Basalt Creek Road Extension bridge art
Basalt Creek Road Extension Bridge concept art (zoomed in aerial)

Open House: Oct. 23, 2019

Open house: June 11, 2019

Basalt Creek Transportation Refinement Plan Alternatives

City concept plans


The three levels of environmental review for FHWA are categorical exclusion, environmental assessment, and environmental impact statement. The initial recommendation for this project is a “categorical exclusion.”  More information can be found on the Federal Highway Administration website and in Oregon Department of Transportation NEPA Manual

The classification was recommended by the Oregon Department of Transportation (ODOT) and tentatively confirmed by the Federal Highway Administration (FHWA). ODOT environmental resource specialists reviewed the environmental scope of the project and conducted a site visit with the County. During the site visit, the ODOT environmental resource specialists met with several property owners along the canyon and were able to access the canyon. FHWA requested a preliminary historic analysis and noise report, which were conducted and submitted. The initial recommendation was a categorical exclusion.

No. The project is conducting the necessary environmental studies in accordance with local, state and federal requirements.

Yes. All environmental reports will be submitted to FHWA, who will review the project and its impacts. FHWA may conclude additional analysis is needed and upgrade the classification to an Environmental Assessment (EA).

Reports to be submitted include:

  • Noise analysis
  • Biological resource report
  • Threatened and endangered species study
  • Wetland delineation report
  • Wetland functional assessment report
  • Archaeological and historic resources reports
  • Hazardous Materials Corridor Assessment
  • Stormwater report, and
  • Joint permit application to the U.S. Army Corps of Engineers and the Oregon Department of State Lands.

Please note, the Basalt Creek Parkway Extension Project is also producing technical reports such as a hydraulics report and a geotechnical report.

Final reports will be uploaded to the project website in accordance with ORS 135.230 to 135.290.   

No. The project will have a grade of 4%, which is less that the County’s 10% maximum and less than ODOT’s 6% maximum. 

4% grade graphic for Basalt Creek Parkway Extension

The noise analysis assessed noise impacts during the peak commute hours. Using ODOT noise abatement criteria which is based on FHWA criteria, building sound walls along the road would have a limited benefit are not cost-effective, therefore are not recommended.

Temporary impacts to the canyon are expected during bridge construction. Impacted areas will be rehabilitated.

The work site will be left in a secure manner daily to ensure safety of people and animals. It is important to note, the wildlife in the canyon are species familiar with the built environment of humans and tend to avoid areas when people or machinery are present.

The preferred bridge type will minimize long-term impacts with its long spans. After construction, wildlife will be free to roam the canyon in a manner very similar to today.

Yes. The project will adhere to the applicable stormwater codes. The stormwater will be treated and detained in accordance with federal, state and local requirements prior to discharging into the environment.


Back to top