Before SR 106 was established in 1964, two older highways, PSH 14 (1937–1955, left) and PSH 21 (1955–1964, right) used the current route of the highway.
Recently, the Washington State Department of Transportation (WSDOT) has arranged and completed some minor construction projects along the SR 106 corridor. The first project replaced a culvert over Skobob Creek with a bridge;[12] the project was completed in December 2005 and was located 0.85 miles (1.37 km) east of Skokomish.[1][12][13] In 2007, WSDOT installed a traffic signal at the SR 106 / SR 3 intersection south of Belfair.[14]
^Washington State Department of Transportation (2007). "2007 Annual Traffic Report"(PDF). Archived from the original(PDF) on March 26, 2009. Retrieved June 12, 2009.
^Washington State Legislature (March 19, 1923). "Chapter 185: Primary and Secondary Highways". Session Laws of the State of Washington (1923 ed.). Olympia, Washington: Washington State Legislature. p. 631. Retrieved June 12, 2009.
^Washington State Legislature (March 18, 1937). "Chapter 190: Establishment of Primary State Highways". Session Laws of the State of Washington (1937 ed.). Olympia, Washington: Washington State Legislature. p. 1001. Retrieved June 12, 2009.
^Washington State Legislature (1955). "Chapter 83". Session Laws of the State of Washington (1955 ed.). Olympia, Washington: Washington State Legislature.
^C. G. Prahl (December 1, 1965). "Identification of State Highways"(PDF). Washington State Highway Commission, Department of Highways. p. 12. Retrieved June 12, 2009.