35th Ave SE Corridor - Phase I (180th St SE to 152nd St SE (Seattle Hill Rd)

February 2017 Update

Open House: 35th Avenue SE, Seattle Hill Road, and 156th Street SE
Public Works is hosting an open house to discuss these three projects in the unincorporated Mill Creek/Bothell area. 
  • When: Thursday, February 23, 2017 – stop by anytime between 5:30 and 7:30 p.m.
  • Where: Mill Creek Elementary School in the Cafeteria
  • What: Residents of the area, commuters, and families of nearby schools are invited to discuss the three projects. Staff will be available to answer questions about the Seattle Hill Road construction, review the proposed road improvements to the section of 35th Avenue SE, and gather feedback on potential designs for the 156th Street SE project.
Questions or comments about the open house should be directed to Catherine Higgins via email or by calling 425-388-3053.


Snohomish County is proposing improvements to the 35th Ave. SE corridor between 180th St SE and 152nd St SE (Seattle Hill Road). The corridor is an important north-south route for Snohomish County residents in a rapidly developing area of the county. The proposal includes adding bike lanes, center turn lanes, planter strips, sidewalks, and stormwater detention and treatment facilities. The proposed improvements will improve traffic flow and help ease congestion during busy morning and afternoon commutes. The addition of continuous center turn lanes will reduce delays caused by turning vehicles. The plan also includes dedicated bike lanes and sidewalks on both sides of the road.

35th Ave SE Corridor – Phase 2 between SR 524 to 180th St SE will be
constructed after 35th Ave SE Phase 1 is completed.


2011-2018: Design, survey, environmental review, right-of-way acquisition
The process of developing road projects takes several years. Many factors must be considered, including: location of homes; public right-of-way; stormwater runoff, drainage and water quality; wetlands and buffers; hilly terrain; sight distance; soils; traffic volumes; accident history; vehicle and pedestrian access; location of utilities; and information that residents provide about the area.

• 2011: Completed surveying the topography of the project area
• 2013: Completed environmental review
• 2015: Right of way purchase in progress
• 2018: Construction anticipated to begin

Environmental Review

An environmental review was completed in compliance with the SEPA. An environmental checklist was prepared on July 26, 2013.

A Determination of Non-significance (DNS) and Notice of Land Disturbing Activity (LDA) Permit were issued on July 26, 2013. They are also available for viewing at Snohomish County Public Works during normal business hours:

• Cover Letter
• DNS and Land Disturbing Activity Permit
• Environmental Checklist
• SEPA / LDA Notice: August 4, 2013
• SEPA / LDA Notice Sign Posted: August 2, 2013

Public Comment & Appeal Period

The DNS and LDA 21-day comment and appeal period ended on August 26, 2013. Stephanie Cotton, 425-262-2481, is the contact for the environmental process.


As part of the widening project, Snohomish County will need to purchase right-of-way adjacent to the road from property owners along 35th Ave SE. Right of way purchase is in progress and is expected to be completed by 2017. More Information on the right-of-way acquisition process contact Kurt Lytle at 425-388-6457. The process is also included in the Before we Build Pamphlet.