List of state highways in Idaho
Highway markers for State Highways 3, 75 and 200 | |
| Highway names | |
|---|---|
| Interstates | Interstate X (I-X) |
| US Highways | U.S. Route X (US-X) |
| System links | |
| |
The Idaho Transportation Department is responsible for the establishment and classification of a state highway network, including 5,000 miles (8,000 km) of roads that are classified as Interstate highways, U.S. highways, and state highways.[1]
History
Instead of numbering its highways, Idaho had a system of lettered Sampson Trails in the 1920s.[2] They were marked by Charles B. Sampson of Boise at no expense to the state.[3] By the mid-1930s, the state had adopted a more standard system of numbered state highways.[4][5]
The following trails were marked:[2]
- 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 (today's SH-55)
- E, not on the 1926 map
- F, Boise to Blackfoot via Stanley; became SH-21, SH-17, US-93 (today's SH-75), and SH-27
- G, Mountain Home to Picabo via Fairfield; became SH-22 (today's US-20)
- H, Bliss to Trude via Arco; became SH-24, SH-23, SH-22, SH-29, and an unnumbered road (today's US-20 and US-26)
- 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;[citation needed] 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 (today's SH-75)
- W, not on the 1926 map
- X, not on the 1926 map
- Y, Bonners Ferry to Canada; became US-95
State highways
| Number | Length (mi)[6] | Length (km) | Southern or western terminus | Northern or eastern terminus | Formed[7] | Removed | Notes | |
|---|---|---|---|---|---|---|---|---|
 SH-1
|
12.279 | 19.761 | US-95 near Copeland | BC 21 at Porthill | 1932 | current | ||
 SH-3
|
117.680 | 189.388 | US-12 near Spalding | I-90 near Rose Lake | — | — | ||
 SH-4
|
7.380 | 11.877 | I-90 in Wallace | National Forest Road No. 7623 at Burke | 1926 | current | ||
 SH-5
|
19.140 | 30.803 | US-95 in Plummer | SH-3 in Saint Maries | — | — | ||
 SH-6
|
40.645 | 65.412 | WA 272 near Potlatch | SH-3 near Santa | — | — | ||
 SH-7
|
16.563 | 26.656 | Russell Ridge Road near Orofino | Old Highway 7 in Ahsahka | 1919 | current | ||
 SH-8
|
53.589 | 86.243 | WA 270 in Moscow | 1st Street in Elk River | — | — | ||
 SH-9
|
13.522 | 21.762 | SH-8 near Deary | SH-6 near Harvard | — | — | ||
 SH-11
|
42.481 | 68.367 | US-12 in Greer | Forest Service Road No. 247 near Headquarters | — | — | ||
 SH-13
|
26.390 | 42.471 | US-95 in Grangeville | US-12 near Kooskia | 1919 | current | ||
 SH-14
|
49.515 | 79.687 | SH-8 near Harpster | Airport Road in Elk City | — | — | ||
 SH-16
|
16.005 | 25.758 | US-26 near Star | SH-52 in Emmett | — | — | ||
 SH-19
|
19.915 | 32.050 | OR 201 near Homedale | I-84 Business in Caldwell | — | — | ||
 SH-21
|
130.869 | 210.613 | I-84 in Boise | SH-75 in Stanley | — | — | ||
 SH-22
|
43.936 | 70.708 | SH-33 near Howe | I-15 in Dubois | — | — | ||
 SH-24
|
67.533 | 108.684 | I-84 / US-30 in Heyburn | US-93 in Shoshone | — | — | ||
 SH-25
|
58.048 | 93.419 | I-84 near Jerome | I-84 / SH-77 near Declo | — | — | ||
 SH-27
|
26.561 | 42.746 | Main Street in Oakley | SH-25 in Paul | — | — | ||
 SH-28
|
135.645 | 218.299 | SH-33 near Mud Lake | US-93 in Salmon | 1916 | current | ||
 SH-29
|
13.614 | 21.910 | SH-28 in Leadore | MT S-324 at Bannock Pass | — | — | ||
 SH-31
|
21.025 | 33.836 | US-26 in Swan Valley | SH-33 in Victor | — | — | ||
 SH-32
|
28.386 | 45.683 | SH-33 near Tetonia | SH-47 near Ashton | — | — | ||
 SH-33
|
155.084 | 249.584 | US-20 / US-26 near Arco | WYO 22 near Victor | — | — | ||
 SH-34
|
105.980 | 170.558 | US-91 / SH-36 in Preston | WYO 239 near Freedom | 1919 | current | ||
 SH-36
|
73.313 | 117.986 | I-15 near Malad City | US-89 in Ovid | — | — | ||
 SH-37
|
31.231 | 50.261 | Onedia–Power county line near Holbrook | I-86 near American Falls | — | — | ||
 SH-38
|
23.438 | 37.720 | North Holbrook Road near Holbrook | I-15 in Malad City | — | — | ||
 SH-39
|
52.924 | 85.173 | I-86 in American Falls | US-26 in Blackfoot | — | — | ||
 SH-40
|
2.737 | 4.405 | I-15 near Downey | US-91 in Downey | 1922 | current | ||
 SH-41
|
39.058 | 62.858 | I-90 in Post Falls | US-2 in Oldtown | 1931 | current | ||
 SH-43
|
3.868 | 6.225 | US-26 at Beachs Corner | US-20 in Ucon | — | — | ||
 SH-44
|
23.089 | 37.158 | I-84 near Caldwell | US-20 / US-26 | — | — | ||
 SH-45
|
17.985 | 28.944 | SH-78 at Walters Ferry | I-84 Business in Nampa | — | — | ||
 SH-46
|
43.052 | 69.285 | I-84 near Wendell | US-20 near Fairfield | — | — | ||
 SH-47
|
12.420 | 19.988 | US-20 in Ashton | Caribou-Targhee National Forest near Warm River | 1932 | current | ||
 SH-48
|
24.409 | 39.282 | I-15 near Roberts | US-26 Business in Ririe | 1930 | current | ||
 SH-50
|
8.092 | 13.023 | US-30 near Kimberly | SH-25 near Eden | — | — | ||
 SH-51
|
93.598 | 150.631 | NV 225 near Owyhee, NV | I-84 Business in Mountain Home | 1932 | current | ||
 SH-52
|
54.126 | 87.107 | OR 52 in Payette | SH-55 in Horseshoe Bend | — | — | ||
 SH-53
|
14.255 | 22.941 | WA 290 near State Line | US-9 near Hayden | — | — | ||
 SH-54
|
15.440 | 24.848 | SH-41 in Spirit Lake | Main Avenue in Bayview | — | — | ||
 SH-55
|
156.047 | 251.133 | US-95 near Marsing | US-95 in New Meadows | — | — | ||
 SH-57
|
37.230 | 59.916 | US-2 in Priest River | Reeder Creek Road in Nordman | — | — | ||
 SH-58
|
2.943 | 4.736 | WA 278 near Rockford, WA | US-95 near Worley | — | — | ||
 SH-60
|
5.510 | 8.867 | WA 274 near Tekoa, WA | US-95 near Tensed | — | — | ||
 SH-61
|
0.740 | 1.191 | WYO 89 near Geneva | US-89 in Geneva | — | — | ||
 SH-62
|
15.410 | 24.800 | US-95 Business in Craigmont | SH-64 / SH-162 in Nezperce | — | — | ||
 SH-64
|
15.409 | 24.798 | SH-62 / SH-162 in Nezperce | SH-162 in Kamiah | — | — | ||
 SH-66
|
0.992 | 1.596 | Palouse Cove Road near Palouse, WA | US-95 near Viola | — | — | ||
 SH-67
|
8.948 | 14.400 | Mountain Home Air Force Base | SH-51 in Mountain Home | — | — | ||
 SH-69
|
8.012 | 12.894 | Orchard Avenue in Kuna | I-84 / US-30 / SH-55 in Meridian | — | — | ||
 SH-71
|
28.730 | 46.236 | US-95 in Cambridge | OR 86 near Brownlee Dam | — | — | ||
 SH-72
|
1.989 | 3.201 | US-30 near New Plymouth | SH-52 at Hamilton Corner | — | — | ||
 SH-74
|
7.835 | 12.609 | US-93 near Knull | US-30 in Twin Falls | — | — | ||
 SH-75
|
170.666 | 274.660 | US-26 / US-93 in Shoshone | US-93 near Challis | — | — | ||
 SH-77
|
30.676 | 49.368 | SH-81 in Malta | I-84 / SH-25 near Declo | — | — | ||
 SH-78
|
99.720 | 160.484 | SH-55 in Marsing | I-84 Business in Hammett | — | — | ||
 SH-79
|
2.564 | 4.126 | I-84 in Jerome | SH-25 in Jerome | — | — | ||
 SH-81
|
33.978 | 54.682 | SH-77 in Malta | US-30 in Burley | 1972 | current | ||
 SH-87
|
9.133 | 14.698 | US-20 in Island Park | MT 87 near Island Park | — | — | ||
 SH-97
|
35.745 | 57.526 | SH-3 near Harrison | I-90 near Coeur d'Alene | — | — | ||
 SH-99
|
11.686 | 18.807 | SH-3 in Kendrick | SH-8 in Troy | — | — | ||
 SH-128
|
2.198 | 3.537 | WA 128 near Lewiston | US-12 in Lewiston | — | — | ||
 SH-162
|
31.077 | 50.014 | SH-62 / SH-64 in Nezperce | US-12 in Kamiah | — | — | ||
 SH-167
|
16.319 | 26.263 | SH-78 in Grand View | SH-67 near Mountain Home AFB | — | — | ||
 SH-200
|
33.169 | 53.380 | US-2 / US-95 in Ponderay | MT 200 near Clark Fork | — | — | ||
See also
References
- ^ "Frequently Asked Questions". Idaho Transportation Department. Retrieved February 15, 2017.
- ^ a b Rand McNally Auto Road Atlas, 1926, accessed via the Broer Map Library
- ^ 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
- ^ H.M. Gousha Company, Western States road map, published by Standard Oil Company of California, 1935
- ^ Rand McNally and Company, Road map: Idaho, Mont., Wyo., published by Texaco, 1937
- ^ "Milepoint Logs". Idaho Transportation Department. Retrieved February 15, 2017.
- ^ Downing, T.A. (April 15, 1937). "Designated Federal and State Highways Minute Book 09". Idaho Bureau of Highways. Retrieved October 3, 2018 – via Idaho State Archives.