Interstate 15 (Idaho)

Interstate 15
Route information
Maintained by ITD
Length:	196.000 mi (315.431 km)
Major junctions
South end:	I-15 at the Utah state line near Woodruff
	US 91 near Arimo US 30 near McCammon I-86 in Pocatello US 26 in Blackfoot US 20 in Idaho Falls
North end:	I‑15 at the Montana state line at Monida Pass
Location
Counties:	Oneida, Bannock, Bingham, Bonneville, Jefferson, Clark
Highway system
Interstate Highway System Main Auxiliary Suffixed Business Future State Highways in Idaho Interstate U.S. State ← SH 14 SH 16 →

Interstate 15 (I-15) is a part of the Interstate Highway System that runs from San Diego, California, to Sweetgrass, Montana. In Idaho, the Interstate Highway runs exactly 196 miles (315 km) from the Utah state line near Woodruff north to the Montana state line at Monida Pass. I-15 is the primary north–south highway of Eastern Idaho. The Interstate Highway connects Pocatello and Idaho Falls, the fourth and fifth largest cities in Idaho, and the smaller county seats of Malad City, Blackfoot, and Dubois. I-15 connects all of those cities with Salt Lake City to the south and Butte to the north. The Interstate has business loops through McCammon, Inkom, Pocatello, Blackfoot, and Idaho Falls.

I-15 is designated the Veterans Memorial Highway for its entire length in Idaho.

I-15 enters Oneida County from Box Elder County, Utah, south of the hamlet of Woodruff. The four-lane Interstate heads north parallel to the Union Pacific Railroad's Malad Subdivision rail line, a road named Old Highway 191, and the Malad River along the eastern edge of the wide Malad Valley adjacent to the Malad Range. I-15 has a diamond interchange with Woodruff Road at Woodruff and follows the western edge of Caribou National Forest. The highway passes just to the east of the county seat, Malad City, where the highway has a diamond interchange with the eastern end of Idaho State Highway 38 (SH 38). I-15 continues along Deep Creek to another diamond interchange with the western end of SH 36. From there, the Interstate follows the narrow valley of Devil Creek between the Bannock Range to the east and Elkhorn Mountain to the west. I-15 has one more diamond interchange in Oneida County next to Devils Creek Reservoir before the highway reaches Malad Summit, where the highway leaves the Great Salt Lake watershed and enters the Snake River watershed.

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Wikipedia