U.S. Route 30 in Idaho

U.S. Highway 30
US 30 highlighted in red
Route information
Maintained by ITD
Length	455.481 mi[1] (733.026 km)
Existed	1926 (1926)–present
Tourist routes	Thousand Springs Scenic Byway
Major junctions
West end	US 30 in Fruitland
Major intersections	US 95 in Fruitland I-84 near New Plymouth US 20 / US 26 near Caldwell I-184 in Boise US 93 near Filer I-84 / SH-24 in Heyburn I-86 near Declo I-15 BL / US 91 in Pocatello I-15 in Pocatello US 89 in Montpelier
East end	US 30 near Dingle
Location
Country	United States
State	Idaho
Counties	Payette, Canyon, Ada, Elmore, Gooding, Twin Falls, Cassia, Minidoka, Power, Bannock, Caribou, Bear Lake
Highway system
United States Numbered Highway System List Special Divided Idaho State Highway System Interstate US State
← 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 30 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.

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]

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]

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.

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]

County	Location	mi[1][12][13][14]	km	Exit	Destinations	Notes
Payette	Fruitland	0.000	0.000		US 30 west – Ontario	Continuation west into Oregon
		0.610	0.982		US 95 north (North Whitley Drive) / NW 16th Street – Payette, Weiser	Western end of US 95 concurrency
	​	21.530	34.649		US 95 south to I-84 – Parma, Winnemucca	Eastern end of US 95 concurrency; destinations signed eastbound only
	​	27.940	44.965		SH-72 east – Emmett	Western end of SH-72
	​	31.073– 31.175	50.007– 50.171	9	I-84 west – Ontario	Western end of I-84 concurrency
	​	12.906	20.770	13	Black Canyon Junction
Canyon	​	17.335	27.898	17	Sand Hollow
	​	24.839	39.974	25	SH-44 – Middleton
	​	25.994	41.833	26	US 20 west / US 26 west – Parma, Notus	Western end of US 20/US 26 concurrency
	Caldwell	26.723	43.006	27	I-84 BL east to SH-19 – Caldwell, Wilder, Homedale
		27.620	44.450	28	10th Avenue – Caldwell City Center
		28.650	46.108	29	US 20 east / US 26 east (Franklin Road)	Eastern end of US 20/US 26 concurrency
	Nampa	33.539	53.976	33	SH-55 south / Midland Boulevard – Nampa, Marsing	Western end of SH-55 concurrency; signed as exits 33A (SH-55) and 33B (Midland Blvd.) westbound
		34.965	56.271	35	Northside Boulevard
		35.985	57.912	36	Franklin Boulevard
		37.945	61.067	38	I-84 BL west (Garrity Boulevard) – Nampa, Murphy
Ada	Meridian	42.000	67.592	42	Ten Mile Road
		44.007	70.822	44	SH-69 – Meridian, Kuna
		45.998	74.027	46	SH-55 north – McCall, Eagle	Eastern end of SH-55 concurrency
	Boise	49.307	79.352	49	I-184 east / Franklin Road – City Center	I-184 exit 0
		50.140	80.693	50	Cole Road / Overland Road	Signed as exits 50A (Overland Rd. west) and 50B (Cole/Overland) eastbound, and 50A (Cole/Overland) and 50B (Overland Rd. east) westbound
		51.997	83.681	52	Orchard Street
		53.483	86.073	53	Vista Avenue – Boise Airport
		54.485	87.685	54	US 20 / US 26 west (Broadway Avenue)	Western end of US 20/US 26 concurrency
		56.932	91.623	57	SH-21 (Gowen Road) – Idaho City
	​	59.510	95.772	59	S. Eisenman Road / Memory Road	Signed as exits 59A (S. Eisenman Rd.) and 59B (Memory Rd.) eastbound
	​	63.517	102.221	64	Blacks Creek Road – Kuna
	Regina	70.772	113.896	71	Mayfield, Orchard
Elmore	​	74.333	119.627	74	Simco Road
	​	90.280	145.292	90	I-84 BL east to SH-51 / SH-67 – Mountain Home, Bruneau	Eastbound signage
					West Mountain Home	Westbound signage
	Mountain Home	95.193	153.198	95	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
	​	99.570	160.242	99	Old Oregon Trail Road – Mountain Home
	​	111.800	179.925	112	I-84 BL east to SH-78 – Hammett
	​	113.856	183.233	114	I-84 BL west to SH-78 / Cold Springs Road – Hammett	Westbound exit and eastbound entrance
	​	120.149	193.361	120	I-84 BL east – Glenns Ferry	Eastbound exit and westbound entrance
	​	121.094	194.882	121	I-84 BL west – King Hill, Glenns Ferry
	​	125.159	201.424	125	Paradise Valley
	​	128.993	207.594	129	King Hill
Gooding	Bliss	172.595	277.765	137	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.
		172.663	277.874		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 Falls	Buhl				North 1500 East Road (SH-46 north)	Southern end of SH-46
	​	211.645– 212.612	340.610– 342.166		US 93 – Sun Valley, Jackpot, Wells	Western end of US 93 Bus. concurrency; western end of US 93 Bus.; interchange; Sun Valley and Jackpot signed eastbound, Wells westbound
	Twin Falls	217.199– 217.282	349.548– 349.681		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
		217.915	350.700		SH-74 south (Shoshone Street South) / Shoshone Street East – Wells	Northern end of SH-74
	​	223.505	359.696		SH-50 east to I-84 / North 3500 East – Burley, Pocatello	Western end of SH-50
Cassia	Burley	257.481	414.376		I-84 BL west / SH-27 (Overland Avenue) – Oakley, Paul	Western end of I-84 Bus. concurrency
		258.628– 258.723	416.221– 416.374		SH-81 east / Airport Way – Declo	Western end of SH-81
Minidoka	Heyburn	261.123– 261.754	420.237– 421.252	211	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
Cassia	​	216.395	348.254	216	SH-25 / SH-77 – Albion, Rupert, Declo
Minidoka	​	272.947– 0.000	439.266– 0.000	222 1	I-84 east / I-86 begins – Ogden, Salt Lake	Eastern end of I-84 concurrency; Western end of I-86 concurrency
Cassia	​	14.807	23.830	15	Raft River Area
Power	​	20.590	33.136	21	Coldwater Area
	​	28.100	45.223	28	Massacre Rocks State Park
	​	32.620	52.497	33	Neeley Area
	American Falls	36.123	58.134	36	SH-37 south / I-86 BL east – Rockland, American Falls
		40.110	64.551	40	SH-39 north / I-86 BL west – Aberdeen, American Falls
	​	44.327	71.337	44	Seagull Bay
	​	49.152	79.102	49	Rainbow Road
	​	52.491	84.476	52	Arbon Valley
	​	55.551	89.401	56	Pocatello Regional Airport
	​	330.820– 330.930	532.403– 532.580	58	I-86 east / Tank Farm Road – Idaho Falls	Eastern end of I-86 concurrency; I-86 exit 58
Bannock	Pocatello	335.778	540.382		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
		339.220	545.922	67	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
	Portneuf	63.037	101.448	63	Portneuf Road – Portneuf Area
	Inkom	57.694	92.849	58	I-15 BL south – Inkom	Southbound exit, northbound entrance
		56.646	91.163	57	I-15 BL north – Inkom	Northbound exit, southbound entrance
	​	359.493	578.548	47	I-15 south / US 91 south / East Merrill Road – Arimo, Salt Lake	Eastern end of I-15/US 91 concurrency
Caribou	​	386.450	621.931		SH-34 south / Old US 30 – Grace, Bancroft	Western end of SH-34 concurrency; Bancroft signed westbound only
	Soda Springs	405.543	652.658		SH-34 north (South Third Street) / South Third Street – Wayan, Jackson	Eastern end of SH-34 concurrency
Bear Lake	Montpelier	434.712	699.601		US 89 north (Clay Street) / Clay Street	Western end of US 89 concurrency; destinations signed westbound only
		435.015	700.089		US 89 south (Washington Street) / Washington Street – Paris, Bear Lake, Logan, Salt Lake	Eastern end of US 89 concurrency; only Paris signed westbound
	​	455.481	733.026		US 30 east	Continuation into Wyoming
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus