Our maintenance crews use integrated roadside vegetation management plans (IRVM) to select the right tools, techniques and timing, for taking care of the soil and greenery alongside highways.

Every year, our training programs are updated based on the successes and lessons learned. Any public group or person is welcome to also submit their own information to help us stay up to date.

The plans list intended routine maintenance activities, weed control priorities, sensitive area locations and other relevant information. They also include a record-keeping system of mapping and tracking work through our Highway Activity Tracking System (HATS).

For questions and comments on the plans, contact Ray Willard at 360-705-7865.

Eastern Region

• Area 1 - Most of Spokane, south Pend Oreille, and southeast Stevens Counties (pdf 705 kb)
• Area 2 - Whitman, southeast Adams, and a small portion of south Spokane Counties (pdf 693 kb)
• Area 3 - Adams (all but southeast) and Lincoln Counties (pdf 1 mb)
• Area 4 - Ferry, Stevens (all but southeast), and north Pend Oreille Counties (pdf 497 kb)

Northwest Region  

• Area 1 - Whatcom and northwest Skagit Counties (pdf 2 mb)
• Area 2 - Skagit (all but northwest) and north Snohomish Counties (pdf 2 mb)
• Area 3 - South Snohomish and northeast King Counties  (pdf 270 kb)
• Area 4 - South King and east Pierce Counties (pdf 772 kb)
• Area 5 - Seattle-Bellevue and central King County (pdf 2 mb)

North Central Region

• Area 1 - Chelan, west Douglas, east King and north Kittitas Counties  (pdf 789 kb)
• Area 2 - Grant, west Adams and a small portion of north Franklin Counties (pdf 1 mb)
• Area 3 - Okanogan, east Douglas and east Skagit Counties (pdf 1 mb)

Olympic Region

• IRVM Plan - Pierce, Thurston, Kitsap, Jefferson, Clallam, Mason and Grays Harbor Counties  (pdf 2 mb)

South Central Region 

• Area 1 - North Kittitas and east King Counties (pdf 2 mb)
• Area 2 -Yakima and south Kittitas Counties (pdf 1 mb)
• Area 3 - Benton, Franklin, southeast Yakima, and southwest Walla Walla Counties (pdf 592 kb)
• Area 4 - Asotin, Garfield, Columbia, and Walla Walla (all but southwest) Counties (pdf 759 kb) 

Southwest Region

• IRVM Plan - Lewis, Cowlitz, Clark, Skamania, Pacific, Wahkiakum and Klickitat Counties (pdf 2 mb)