Wikipedia:WikiProject U.S. Roads/California/History/Routes in adjoining states

Arizona

 * I-8: part of the 1914 plan (Borderland Highway)
 * I-10: added ca. 1927 (shown on 1927 federal 7% map on page 9 of but not the 1927 list on page 15)
 * SR 72: added between 1930 and 1935
 * I-40: part of the 1914 plan (Santa Fe Highway)

Nevada

 * US 95: SR 5 in 1919
 * SR 164: SR 68 by 1940
 * I-15: SR 6 in 1919, but only north of Jean until 1921
 * SR 161: SR 53 by 1935
 * SR 16 by 1929
 * SR 372: SR 52 by 1937
 * SR 373: SR 29 by 1933
 * SR 374: SR 58 by 1937
 * SR 267: SR 72 by 1942
 * SR 71 by 1942
 * SR 266: SR 3 in 1917
 * SR 264: SR 3A by 1933
 * US 6: SR 10 by 1929
 * SR 359, SR 31 by 1933; later cut back and reextended to the present crossing by 1947
 * SR 3C by 1946
 * SR 338: SR 22 by 1929
 * US 395: SR 19 by 1929
 * SR 88: SR 37 by 1934
 * US 50: SR 3 in 1917
 * SR 28: SR 28 by 1932?
 * I-80: SR 1 in 1917
 * US 395: SR 9 in 1921
 * SR 81 by 1942
 * SR 8 in 1921; SR 8A by 1929

Oregon

 * 19 Fremont Highway: included in 1917 plan
 * 50 Klamath Falls-Malin Highway: 4 from 1919 to 1939, then 50
 * 426 Hatfield Highway: 1937
 * 4 The Dalles-California Highway: included in 1917 plan, but moved to Malin in 1919; 420 Midland Highway in 1931; 50 Klamath Falls-Weed Highway ca. 1935?; 4 moved back in 1939
 * 1 Pacific Highway: included in 1917 plan
 * 25 Redwood Highway: included in 1917 plan
 * 9 Oregon Coast Highway: included in 1917 plan as 3