U.S. Route 30 in Idaho

From the AARoads Wiki: Read about the road before you go
Jump to navigation Jump to search

U.S. Highway 30

US 30 highlighted in red
Route information
Maintained by ITD
Length455.481 mi[1] (733.026 km)
Existed1926 (1926)–present
Thousand Springs Scenic Byway
Major junctions
West end US 30 in Fruitland
Major intersections
East end US 30 near Dingle
CountryUnited States
CountiesPayette, Canyon, Ada, Elmore, Gooding, Twin Falls, Cassia, Minidoka, Power, Bannock, Caribou, Bear Lake
Highway system
  • Idaho State Highway System
SH-29 SH-31

U.S. Route 30 (US 30) runs northwest–southeast across the southern half of lower Idaho for 455.481 miles (733.026 km). US 30 enters the state from Oregon across the Snake River in Fruitland and exits into Wyoming east of Dingle. US 26 runs through the large population centers of Boise, Twin Falls, and Pocatello, as well as a plethora of smaller communities from Fruitland to Montpelier. The Thousand Springs Scenic Byway is a picturesque section of US 30 in southern Idaho between the towns of Bliss and Buhl, dipping down into the Hagerman Valley and a canyon of the Snake River.

The highway has four extensive concurrencies with Interstate Highways: Interstate 84 (I-84) twice, I-86, and I-15. Outside of its Interstate concurrencies, the route is largely two-lane and rural outside of portions through major towns and cities.

Route description

Oregon state line to Boise

After crossing the Snake River, US 30 enters Fruitland as NW 16th Street before intersecting US 95. The route then turns south along US 95 (Whitley Drive in Fruitland). Just north of the I-84 interchange, US 30 turns east toward New Plymouth. In New Plymouth, US 30 bends south, then southeast, and then south again. Just northeast of the Langley Gulch Power Plant, US 30 begins to travel southeast at a diamond interchange, running concurrently with I-84. Along the way, they serve Sand Hollow with one diamond interchange. Just north of Caldwell, US 20 and US 26 enter the freeway southeastward, joining with the concurrency. Entering Caldwell, they then serve I-84 BL/SH-19 and 10th Avenue before both US 20 and US 26 left the freeway together on Franklin Road. In Nampa, I-84 and US 30 then serve SH-55, which then travels eastward concurrently with the two routes. The three routes then serve Northside Boulevard, Franklin Boulevard, and Garrity Boulevard (I-84 BL). In Meridian, the freeway concurrency serves SH-69. On the next exit, SH-55 left the concurrency. Then, in Boise, the freeway comes across I-184 which serves Boise City Center. Between exits 52 and 54, the freeway is situated north adjacent to Boise Airport, with exit 53 serving the main terminal. Also, on exit 54, US 20 and US 26 rejoins the freeway.[2]

Boise to Downtown Pocatello

After leaving Boise, the freeway then serves multiple roads (including SH-21) before reaching Mountain Home. In Mountain Home, the freeway serves I-84 BL. At the next exit, US 20 leaves the freeway alone. The three remaining routes went on to serve several more roads (such as I-84 BL and SH-78). Then, in Bliss, US 30 leaves the freeway and enters the Thousand Springs Scenic Byway. As US 30 approaches I-84, the route turns south and east, serving Hagerman, Buhl, Filer, and Twin Falls. North of Kimberly, the route then leaves the byway. In Burley, the route then intersects SH-27 and SH-81. In Heyburn, the route rejoins I-84 while also intersecting SH-24. They then serve SH-25/SH-77 at the exact interchange. Then, US 30 transitions from I-84 to I-86 on a modified interchange. Both I-86 and US 30 serve more roads and places (including Register Rock, I-86 BL, SH-39, and Pocatello Regional Airport). At exit 58, US 30 leaves the freeway as it approaches Pocatello. At this point, US 30 travels along a road parallel to the railroad. Along the way near downtown, it then begins to run concurrently with I-15 BL and US 91. Shortly after that, the concurrently splits into a one-way pair.[2]

Thousand Springs Scenic Byway

The Thousand Springs Scenic Byway is a picturesque section of US 30 in southern Idaho between the towns of Bliss and Buhl, dipping down into the Hagerman Valley and a canyon of the Snake River. The byway takes its name from the numerous streams and rivulets springing forth out of the east wall of that canyon, many of them plainly visible from the road, with the panoramic river in the foreground. These springs are outlets from the Snake River Aquifer, which flows through thousands of square miles of porous volcanic rock and is one of the largest groundwater systems in the world.[3][4] The aquifer is believed to be fed by the Lost River which disappears into lava flows near Arco, about 90 miles (140 km) northeast of Hagerman.

Downtown Pocatello to Wyoming state line

The concurrency returns to a two-way street. It then comes across I-15 at a diamond interchange. At this point, both U.S. routes continue southeast along I-15 while I-15 BL ends there. The three routes (I-15, US 30, and US 91) then serve even more places such as another I-15 BL in Inkom. At exit 47, US 30 leaves the freeway to serve McCammon. At this point, US 30 begins to meander across several mountains. Between Alexander and Soda Springs, SH-34 runs concurrently with US 30. US 30 then serves more towns through the rest of the state, especially Montpelier. In Montpelier, US 89 briefly runs concurrently with US 30.[2]


US 30 was established in 1926 during the creation of the United States Numbered Highway System, largely along the transcontinental Lincoln Highway, an existing auto trail. The corridor was also preceded by the Old Oregon Trail Highway between Oregon and Utah.[5] The highway crossed southern Idaho by following Route 2 between the Oregon state line and Burley, where it split into two suffixed routes: US 30N through Pocatello and to Montpelier; and US 30S towards Ogden, Utah.[6][7]

Construction of Interstate 80N (now I-84), a superhighway that would parallel US 30 between Portland, Oregon, and northern Utah, began in the 1960s under the Federal-Aid Highway Act of 1956.[6] Various sections of US 30 were relocated onto the new freeway as sections opened over the following two decades. The two suffixed routes were eliminated in 1972 in favor of US 30 remaining on the northern route while generally following I-80N and I-15W (now I-86).[8] A section through Meridian and Downtown Boise was removed in 1980, replaced by a longer overlap with I-84.[9][10] Five years later, the section from Caldwell to Nampa was replaced with Interstate 84 Business.[11]

Major intersections

US 30 west – Ontario
Continuation west into Oregon
US 95 north (North Whitley Drive) / NW 16th Street – Payette, Weiser
Western end of US 95 concurrency

US 95 south to I-84 – Parma, Winnemucca
Eastern end of US 95 concurrency; destinations signed eastbound only
SH-72 east – Emmett
Western end of SH-72
I-84 west – Ontario
Western end of I-84 concurrency
12.90620.77013Black Canyon Junction
Canyon17.33527.89817Sand Hollow
24.83939.97425 SH-44 – Middleton

US 20 west / US 26 west – Parma, Notus
Western end of US 20/US 26 concurrency

I-84 BL east to SH-19 – Caldwell, Wilder, Homedale
27.62044.4502810th Avenue – Caldwell City Center

US 20 east / US 26 east (Franklin Road)
Eastern end of US 20/US 26 concurrency
SH-55 south / Midland Boulevard – Nampa, Marsing
Western end of SH-55 concurrency; signed as exits 33A (SH-55) and 33B (Midland Blvd.) westbound
34.96556.27135Northside Boulevard
35.98557.91236Franklin Boulevard
I-84 BL west (Garrity Boulevard) – Nampa, Murphy
AdaMeridian42.00067.59242Ten Mile Road
44.00770.82244 SH-69 – Meridian, Kuna
SH-55 north – McCall, Eagle
Eastern end of SH-55 concurrency
I-184 east / Franklin Road – City Center
I-184 exit 0
50.14080.69350Cole Road / Overland RoadSigned as exits 50A (Overland Rd. west) and 50B (Cole/Overland) eastbound, and 50A (Cole/Overland) and 50B (Overland Rd. east) westbound
51.99783.68152Orchard Street
53.48386.07353Vista Avenue – Boise Airport
US 20 / US 26 west (Broadway Avenue)
Western end of US 20/US 26 concurrency
56.93291.62357 SH-21 (Gowen Road) – Idaho City
59.51095.77259S. Eisenman Road / Memory RoadSigned as exits 59A (S. Eisenman Rd.) and 59B (Memory Rd.) eastbound
63.517102.22164Blacks Creek Road – Kuna
Regina70.772113.89671Mayfield, Orchard
Elmore74.333119.62774Simco Road

I-84 BL east to SH-51 / SH-67 – Mountain Home, Bruneau
Eastbound signage
West Mountain HomeWestbound signage
Mountain Home95.193153.19895

US 20 east (Sun Valley Highway) / I-84 BL west / SH-51 south (American Legion Boulevard) to SH-67 – Mountain Home, Fairfield
Eastern end of US 20 concurrency
99.570160.24299Old Oregon Trail Road – Mountain Home

I-84 BL east to SH-78 – Hammett

I-84 BL west to SH-78 / Cold Springs Road – Hammett
Westbound exit and eastbound entrance
I-84 BL east – Glenns Ferry
Eastbound exit and westbound entrance
I-84 BL west – King Hill, Glenns Ferry
125.159201.424125Paradise Valley
128.993207.594129King Hill

I-84 east / US 26 east / Old U.S. 30 – Twin Falls
Eastern end of I-84/US 26 concurrency;western end of US 95 concurrency western end of I-84 Bus. overlap; western terminus of I-84 Bus.

To I-84 / US 26 (I-84 Bus. east) / South 750 East – Twin Falls, Gooding
Eastern end of I-84 Bus. concurrency; Twin Falls signed eastbound, Gooding westbound
Twin FallsBuhlNorth 1500 East Road (SH-46 north)Southern end of SH-46
US 93 – Sun Valley, Jackpot, WellsWestern end of US 93 Bus. concurrency; western end of US 93 Bus.; interchange; Sun Valley and Jackpot signed eastbound, Wells westbound
Twin Falls217.199–

US 93 Bus. north (Addison Avenue) to I-84 – Jerome, Sun Valley
Eastern end of US 93 Bus. concurrency; to I-84, destinations signed westbound only
SH-74 south (Shoshone Street South) / Shoshone Street East – Wells
Northern end of SH-74

SH-50 east to I-84 / North 3500 East – Burley, Pocatello
Western end of SH-50
I-84 BL west / SH-27 (Overland Avenue) – Oakley, Paul
Western end of I-84 Bus. concurrency

SH-81 east / Airport Way – Declo
Western end of SH-81

I-84 west / SH-24 west – Twin Falls, Rupert
Eastern end of I-84 Bus. concurrency; western end of I-84 concurrency;Rupert signed eastbound only; eastern end of I-84 Bus.; western end of SH-84
Cassia216.395348.254216 SH-25 / SH-77 – Albion, Rupert, Declo

I-84 east / I-86 begins – Ogden, Salt Lake
Eastern end of I-84 concurrency; Western end of I-86 concurrency
Cassia14.80723.83015Raft River Area
Power20.59033.13621Coldwater Area
28.10045.22328Massacre Rocks State Park
32.62052.49733Neeley Area
American Falls36.12358.13436

SH-37 south / I-86 BL east – Rockland, American Falls

SH-39 north / I-86 BL west – Aberdeen, American Falls
44.32771.33744Seagull Bay
49.15279.10249Rainbow Road
52.49184.47652Arbon Valley
55.55189.40156Pocatello Regional Airport
I-86 east / Tank Farm Road – Idaho Falls
Eastern end of I-86 concurrency; I-86 exit 58

I-15 BL north / US 91 north (Yellowstone Avenue) to I-15 / East Oak Street – Blackfoot, Idaho Falls
Western end of I-15 Bus./US 91 concurrency; to I-15 signed westbound only
I-15 north / South Fifth Avenue – Idaho Falls
Eastern end of I-15 Bus. concurrency; western end of I-15 concurrency; southern end of I-15 Bus.; I-15 exit 67
Portneuf63.037101.44863Portneuf Road – Portneuf Area
I-15 BL south – Inkom
Southbound exit, northbound entrance
I-15 BL north – Inkom
Northbound exit, southbound entrance

I-15 south / US 91 south / East Merrill Road – Arimo, Salt Lake
Eastern end of I-15/US 91 concurrency
SH-34 south / Old US 30 – Grace, Bancroft
Western end of SH-34 concurrency; Bancroft signed westbound only
Soda Springs405.543652.658
SH-34 north (South Third Street) / South Third Street – Wayan, Jackson
Eastern end of SH-34 concurrency
Bear LakeMontpelier434.712699.601
US 89 north (Clay Street) / Clay Street
Western end of US 89 concurrency; destinations signed westbound only
US 89 south (Washington Street) / Washington Street – Paris, Bear Lake, Logan, Salt Lake
Eastern end of US 89 concurrency; only Paris signed westbound
US 30 east
Continuation into Wyoming
1.000 mi = 1.609 km; 1.000 km = 0.621 mi


  1. ^ a b "State Highway System Route: 0030" (PDF). Idaho Transportation Department Milepoint Log. Idaho Transportation Department. January 25, 2016. Retrieved November 7, 2020.
  2. ^ a b c Google (October 10, 2021). "Overview Map of US 30 in Idaho" (Map). Google Maps. Google. Retrieved October 10, 2021.
  3. ^ "Thousand Springs Scenic Byway". America's Byways. Federal Highway Administration. Archived from the original on August 14, 2013. Retrieved May 2, 2020 – via Wayback Machine.
  4. ^ "America's Scenic Byways: Thousand Springs Scenic Byway". Scenic Byways. Retrieved May 2, 2020.
  5. ^ Weingroff, Richard F. "From Names to Numbers: The Origins of the U.S. Numbered Highway System". Highway History. Federal Highway Administration. Retrieved February 11, 2023.
  6. ^ a b "Interstate 84 – Idaho". Idaho Transportation Department. May 2006. Archived from the original on September 1, 2010. Retrieved February 11, 2023.
  7. ^ "Clason's Road Map of Idaho" (Map). Clason's Touring Atlas. 1:2,000,000. Denver: Clason Map Company. 1931. p. 42. Retrieved February 11, 2023 – via David Rumsey Map Collection.
  8. ^ U.S. Route Numbering Subcommittee (June 20, 1972). "U.S. Route Numbering Subcommittee Agenda Showing Action Taken by the Executive Committee" (Report). Washington, DC: American Association of State Highway Officials. pp. 424–25. Retrieved February 11, 2023 – via Wikisource.
  9. ^ Special Committee on U.S. Route Numbering (June 22, 1980). "Route Numbering Committee Agenda Showing Action Taken by the Executive Committee" (Report). Washington, DC: American Association of State Highway and Transportation Officials. p. 514. Retrieved February 11, 2023 – via Wikisource.
  10. ^ 1979 Rural Traffic Flow Map, State of Idaho (Map). Idaho Transportation Department. 1979. Retrieved February 11, 2023.
  11. ^ Special Committee on U.S. Route Numbering (June 26, 1985). "Route Numbering Committee Agenda" (Report). Washington, DC: American Association of State Highway and Transportation Officials. p. 514. Retrieved February 11, 2023 – via Wikisource.
  12. ^ "State Highway System Route: 0093" (PDF). Idaho Transportation Department Milepoint Log. Idaho Transportation Department. January 12, 2016. Retrieved November 7, 2020.
  13. ^ "State Highway System Route: 0084" (PDF). Idaho Transportation Department Milepoint Log. Idaho Transportation Department. January 12, 2016. Retrieved November 7, 2020.
  14. ^ "State Highway System Route: 0015" (PDF). Idaho Transportation Department Milepoint Log. Idaho Transportation Department. January 25, 2016. Retrieved November 7, 2020.