U.S. Route 30 (US 30) runs northwest–southeast across the southern half of lower Idaho for . US 30 enters the state from Oregon across the

Snake River The Snake River is a major river of the greater Pacific Northwest region in the United States. At long, it is the largest tributary of the Columbia River, in turn, the largest North American river that empties into the Pacific Ocean. The Snake ...

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 I15 may refer to: * Interstate 15, a north–south Interstate Highway in the United States of America * Polikarpov I-15, a Soviet fighter aircraft * I15 (band) "Soulja Girl" is the second single from American rapper Soulja Boy's studio album '' ...

. 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 Sandy 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.

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 Register Rock, near American Falls, Idaho, is a historic site where many Oregon Trail emigrants carved their names on a rock. The rock is located in what is now Massacre Rocks State Park and is now protected by a shelter. It is located west of Am ...

, 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.

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

. 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 The Snake River Aquifer is a large reservoir of groundwater underlying the Snake River Plain in the southern part of the U.S. state of Idaho. Most of the water in the aquifer comes from rain and melting snow that flows onto the plain from the Snake ...

, which flows through thousands of square miles of porous volcanic rock and is one of the largest groundwater systems in the world. The aquifer is believed to be fed by the Lost River which disappears into lava flows near

Arco ARCO ( ) is a brand of gasoline stations currently owned by Marathon Petroleum after BP sold its rights. BP commercializes the brand in Northern California, Oregon and Washington, while Marathon has rights for the rest of the United States an ...

, about 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.

Major intersections

Old Highway 30

Old Highway 30 is an approximately road in

Bannock Bannock may mean: * Bannock (food), a kind of bread, cooked on a stone or griddle * Bannock (Indigenous American), various types of bread, usually prepared by pan-frying * Bannock people, a Native American people of what is now southeastern Oregon ...

and

Caribou Reindeer (in North American English, known as caribou if wild and ''reindeer'' if domesticated) are deer in the genus ''Rangifer''. For the last few decades, reindeer were assigned to one species, ''Rangifer tarandus'', with about 10 subspe ...

counties in southeastern Idaho, United States, that was the former routing of US 30 in the area and forms a northern loop off US 30. It connects US 30 in

Lava Hot Springs Lava Hot Springs is a city along the Portneuf River in eastern Bannock County, Idaho, United States. It is part of the Pocatello, Idaho metropolitan area. The population was 407 at the 2010 census, down from 521 in 2000. Located in the mount ...

with US 30/

Idaho State Highway 34 State Highway 34 (SH-34) is a state highway serving Franklin and Caribou counties in southeastern Idaho. The highway runs northeasterly along the Bear River from Preston towards Soda Springs and the Wyoming state line, where it terminates and ...

(SH 34) north of Grace. The two-lane road, originally part of the highway designated as U.S Route 30 North (US 30N), runs around the northern end of the

Fish Creek Range The Fish Creek Range is a mountain range in Eureka County, Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, Cali ...

. The western end of the road is located within the

Gem Valley Gem Valley is a rural valley in Caribou County, Bannock, and Franklin counties in Idaho, United States, so named for its local gemstones which can be found throughout the valley. It is approximately wide at its widest point east to west, and ...

. The rerouting of US 30 via Fish Creek Summit reduced the distance between Lava Hot Springs and the SH 34 junction by about , but bypassed the city of Bancroft. Notwithstanding, the rerouting still created a more direct route between Lava Hot Springs and Bancroft (via Central Road), reducing driving distance between the cities by about . Old Highway 30 begins at a

T-intersection A three-way junction (or three-way intersection) is a type of road intersection with three arms. A Y junction (or Y intersection) generally has three arms of equal size coming at an acute or obtuse angle to each other; while a T junction (or T ...

on US 30 in the northeastern corner of Lava Hot Springs in Bannock County. From its southern terminus, Old Highway 30 heads northerly, running along the Portneuf River. After only about the road crosses the Portneuf River. After continuing a northerly course along the river, for about another Old Highway 30 passes through the unincorporated community of

Pebble A pebble is a clast of rock with a particle size of based on the Udden-Wentworth scale of sedimentology. Pebbles are generally considered larger than granules ( in diameter) and smaller than cobbles ( in diameter). A rock made predominant ...

. Roughly north of Pebble, the road turn northeasterly to pass by the north end of the Fish Creek Range, while the Portneuf River continues its northerly upstream course. About later, Old Highway 30 turns to head southeasterly for the remainder of its course. Approximately after turning southeast, and after a short jog to the south, the road reaches the city of Bancroft. Roughly its western terminus, Old Highway 30 crosses Main Street in Bancroft. Continuing southeasterly from Bancroft for about , Old Highway 30 passes through what is left of the unincorporated community of Talmage. Roughly beyond Talmage, the road turns due south to its eastern terminus at a junction with US 30/SH 34.

References

{{reflist Idaho Transportation in Payette County, Idaho Transportation in Canyon County, Idaho Transportation in Ada County, Idaho Transportation in Elmore County, Idaho Transportation in Gooding County, Idaho Transportation in Twin Falls County, Idaho Transportation in Cassia County, Idaho Transportation in Minidoka County, Idaho Transportation in Power County, Idaho Transportation in Bannock County, Idaho Transportation in Caribou County, Idaho Transportation in Bear Lake County, Idaho 30