Addresses assigned in mason county are required to be posted within 30 days of their assignment. For questions please contact the department at 360-427-9670 ext 291

The department will notify the Postmaster, PUD, and the local Fire District. It is imperative that you contact your local phone carrier to change your site address information as they update the 911 system for your site. You are also responsible for notifying any personal and business contacts of the change, similar to when you move. The post office will forward your mail from old to new for one year.

When there is a long shared driveway, easement or any situation where there could be confusion in finding an entrance, mile point numbers shall be posted together at the main access point, and at each turn and/or driveway entrance, in contrasting reflective material, to provide direction to the parcel.

Recreational properties, parcels without structures and any other parcels with an assigned address shall affix said address with 30 days of assignment as described herein.

Posting is required to the front of any structure within 30 days of its erection.

Mile point number and or alphabetic unit designation posting shall contrast with any background, should be clearly visible on the front of the structure and shall meet the setback requirements as described below.

Residential address numbers shall be Arabic numerals. Alphabetic designations will be of the English Alphabet.

Single Family residence designations shall be a minimum of 4 inches high with a minimum stroke width of 1/2 inch.

Water front properties with fire boat access shall post mile point numbers in a minimum of 6 inches with a ¾ inch stroke, the mile point number, in contrasting reflective material, on the front of a dock or post visible from the water.

New and existing buildings shall have approved address numbers and or letters, building numbers and or letters or approved building identification posted in conformance with the addressing ordinance.

Multi family residential, small commercial or small business designations:
50 feet or less setback shall post a 6 inch minimum with a ¾ inch stroke.
50 feet or more setback shall post a 12 inch minimum with a 1 ½ inch stroke.
Designating unit on a building will be no less than 4 inches in height.
Designating unit on a door will be no less than 2 inches in height.

Large commercial or industrial structures designations:
100 foot setback or less shall post 18 inch minimum with 2 inch stroke.
100 foot setback or greater shall post 24 inch minimum with 3 inch stroke.