Wikipedia:WikiProject U.S. Roads/Washington/List of pre-1964 highways

has the main sources. appears to be the latest available statutes with the old numbers.

Other branches in 1960:
 * PSH 1 Everett Loop: Evergreen Way and 41st Street? from SR 99 (PSH 1) to Broadway (PSH 1)
 * PSH 1 Marysville Spur: SR 529 from I-5 (PSH 1) north of Everett to Ebey Slough?
 * PSH 1 D Street Connection in Blaine: D Street and I-5 from SR 543 (PSH 1) to Canada
 * SSH 1I Mukilteo Ferry Spur
 * SSH 1W Edmonds Ferry Spur
 * SSH 2D Redmond Spur, SSH 2D to PSH 2 in Redmond
 * PSH 3 Pasco Spur: US 395 and I-182 from Lewis Street (PSH 3) to 4th Avenue (PSH 11)
 * SSH 10B Crown Point Spur
 * SSH 13A Tokeland Branch
 * PSH 14 Manchester Branch: Harper Branch to Manchester
 * PSH 15 Skykomish Connection: new PSH 15 to old PSH 15 in Skykomish
 * PSH 21 Lofall Ferry Connection: PSH 21 to Lofall South Point Ferry
 * SSH 21B Warren Avenue Route: PSH 21 Navy Yard Branch to SSH 21B via Warren Avenue Bridge