The Sampson Trails were a statewide system of lettered highways in the U.S. state of Idaho in the 1920s. They were marked by Charles B. Sampson of Boise at no expense to the state.[Senate Concurrent Resolution No. 8, "a concurrent resolution...to permit Charles B. Sampson to extend the marking system of the Sampson Trail..." passed February 16, 1933] By the mid-1930s, the state had adopted a more standard system of numbered state highways. [H.M. Gousha Company, [http://www.davidrumsey.com/detail?id=1-1-24578-900063 Western States road map] , published by Standard Oil Company of California, 1935] [Rand McNally and Company, [http://www.davidrumsey.com/maps920003-23818.html Road ]
] , published by Texaco, 1937] The following trails were marked:[Rand McNally Auto Road Atlas, 1926, accessed via the [http://www.broermapsonline.org/members/ Broer Map Library] ] ]
*A, Boise to Wyoming via Twin Falls and Pocatello; became US-30 and US-30N
*B, Boise to Canada via Lewiston and Coeur d'Alene; became US-30, US-30N, US-95 , and SH-1
*C, Pocatello to Montana via Idaho Falls; became US-91 and US-191
*D, Boise to New Meadows via Banks; became SH-15
*E, not on the 1926 map
*F, Boise to Blackfoot via Stanley; became SH-21, SH-17, US-93, and SH-27
*G, Mountain Home to Picabo via Fairfield; became SR-22
*H, Bliss to Trude via Arco; became SH-24, SH-23, SH-22, SH-29, and an unnumbered road
*I, Pioneer to Idaho Falls; became an unnumbered road
*J, Nevada to Shoshone via Twin Falls; became US-93
*K, Utah to McCammon via Preston; became US-91
*L, not on the 1926 map
*M, Washington to Montana via Coeur d'Alene; became US-10
*N, Bonners Ferry to Montana;Fact|date=July 2007 became US-2
*O, Oregon to Caldwell; became SH-49 and SH-18
*P, Utah to Downey; became SH-36
*Q, Declo to Fairfield; became SH-25 and SH-46
*R, not on the 1926 map
*S, Oregon to Nampa; became unnumbered road and SH-45
*T, Star to Grimes Pass; became SH-16, unnumbered road, and SH-17
*U, Utah to Montpelier; became SH-35
*V, Hailey to Stanley; became US-93
*W, not on the 1926 map
*X, not on the 1926 map
*Y, Bonners Ferry to Canada; became US-95References
