Idaho State Highway 28

State Highway 28
Route information
Maintained by ITD
Length:	135.6 mi (218.3 km)
Highway system
State Highways in Idaho ← SH-27 SH-29 →

Idaho State Highway 28 is a 120.5 mi (193.9 km) long state highway in Idaho which runs from Salmon, Idaho to Interstate 15 near the Continental Divide.

It runs through Tendoy, Idaho in Lemhi County, Idaho.

Route description

Idaho State Highway 28 begins at an intersection with U.S. Route 93 in the community of Salmon. The highway proceeds southeast through the Lemhi Valley, traveling parallel to the Lemhi River for several miles. The road passes through Leadore, intersecting Idaho State Highway 29 while in the community. Just after exiting the town, the highway passes the Leadore Airport. The roadway continues southeastward for a short distance before bending south and proceeding through the Lemhi Valley. After a long distance, the route bends back southeastward, proceeding to an intersection with State Highway 22. The route continues southeast before passing the Mud Lake Airport, and intersecting ID 33. The road runs concurrently for several miles, traveling eastward. The highway bends southeast, and reaches its western terminus, an interchange with Interstate 15. The entire length of the route is designated as the Sacajawea Historic Byway by the state of Idaho.

Major junctions

County	Location	mi	km	Destinations	Notes
Jefferson	​	0.000	0.000	I-15 / SH-33	eastern terminus and eastern end of ID 33 concurrency
	​	15.150	24.382	SH-33	Western terminus of ID 33 concurrency
	​	15.212	24.481	ID-28 Connector	Northern terminus of ID-28 Connector
	​	17.700	28.485	Monteview Highway
Clark	​	30.610	49.262	SH-22
Lemhi	Leadore	90.229	145.209	SH-29	Western terminus of ID-29
	Tendoy	115.734	186.256	Lewis and Clark Back Country Scenic Byway	Western terminus of the byway
	Salmon	135.645	218.299	US-93 (Challis Street)	Western terminus
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus