Idaho State Highway 51

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

State Highway 51 marker

State Highway 51
SH-51 highlighted in red
Route information
Maintained by ITD
Length93.598 mi[1] (150.631 km)
Major junctions
South end SR 225 near Owyhee, NV
  SH 78
SH 67 near Mountain Home
North end I-84 Business Loop in Mountain Home
CountiesOwyhee, Elmore
Highway system
SH 50SH 52

State Highway 51 (SH-51) is a state highway in southwestern Idaho from Mountain Home south to the Nevada border, where it continues as State Route 225 to Elko. It is the major north–south road in Owyhee County.[2]

As currently configured in the state's official milepoint log, SH-51 terminates at the BL-84 intersection with American Legion Blvd., and is not otherwise officially concurrent/overlaid with BL-84 (where the signs at I-84's Exits 90 and 99 say "To SH-51/To SH-67") or the former section of US-20 that follows American Legion Blvd. to I-84/US-20 east at Exit 95. As of February 2015, some map products such as Google Maps still show SH-51's former overlay with American Legion Blvd.[1]

Route description[edit]

View north from the south end of SH-51

SH-51's northern terminus is in the city of Mountain Home in Elmore County. After turning south from Airbase Rd. and the intersection with SH-67, the road crosses the Snake River into Owyhee County and passes through the towns of Bruneau, Grasmere, and Riddle. About 11.5 miles (18.5 km) from the state border it enters the Duck Valley Indian Reservation.

As the road crosses into Nevada it becomes State Route 225. The reservation's only major town, Owyhee is about 4 miles (6.4 km) south of the state border. After another 95 miles (153 km) through Elko County, SR 225 connects with Interstate 80 in Elko.


The basic route of today's SH-51 was in place as early as the 1930s, mostly as an all-weather gravel road from Mountain Home until it reached the northern boundary of the Duck Valley Indian Reservation, and as an unimproved road on through to the Nevada border and then-NV Route 11 as of the 1937 map.[3]

Major intersections[edit]

OwyheeDuck Valley Indian Reservation0.0000.000 SR 225 south to I‑80 – Owyhee, Elko, RenoSouthern terminus of SH-51
1.4582.346BIA Road 7
2.9254.707BIA Road 8
7.26011.684BIA Road 211
SH 78 west – Grand View, MarsingWestern end of SH-78 overlap
76.582123.247 SH 78 east – Bruneau Dunes State Park, HammettEastern end of SH-78 overlap
Snake River76.979123.886Snake River bridge; Owyhee–Elmore county Line
ElmoreMountain Home88.294142.095West 36th Street SouthOld Grandview Road
90.785146.104 SH 67 west – Mountain Home AFB, Grand View
I-84 Business Loop – Boise, Glenns Ferry, Twin FallsOverlap on I-84 Bus. (old US-26/30) to official northern terminus at American Legion Blvd. (old US-20)
1.000 mi = 1.609 km; 1.000 km = 0.621 mi


Elevation on the highway ranges from a low of 2461 feet (750 m) above sea level at the Snake River crossing,
to a high of 5400 feet (1646 m) at the Nevada border.

Location Milepost Elevation GNIS Feature ID (GNIS search)
Mountain Home 92 3146' - 959 m 374044 43°07′23″N 115°41′32″W / 43.12306°N 115.69222°W / 43.12306; -115.69222
C.J. Strike Reservoir
(Snake River)
76.98 2461' - 750 m 398659 42°56′54″N 115°58′30″W / 42.94833°N 115.97500°W / 42.94833; -115.97500 (C. J. Strike Dam)
Bruneau 71.49 2549' - 777 m 396181 42°52′50″N 115°47′50″W / 42.88056°N 115.79722°W / 42.88056; -115.79722
Grasmere 32.50 5089' - 1551 m 376052 42°22′36″N 115°52′57″W / 42.37667°N 115.88250°W / 42.37667; -115.88250
Riddle 13.49 5367' - 1636 m 398043 42°11′13″N 116°06′37″W / 42.18694°N 116.11028°W / 42.18694; -116.11028
Miller Creek Settlement 6.0 5325' - 1623 m 396897 42°04′54″N 116°07′41″W / 42.08167°N 116.12806°W / 42.08167; -116.12806
Owyhee, Nevada (0) 5400' - 1646 m 842663 41°56′52″N 116°05′55″W / 41.94778°N 116.09861°W / 41.94778; -116.09861


Route map:

KML is from Wikidata
  1. ^ a b c ITD (March 19, 2014). "State Highway 51 Milepoint Log" (PDF). Idaho Transportation Department. Retrieved February 5, 2015.
  2. ^ Conley, Cort (1982). Idaho for the curious: a guide. Cambridge, Idaho: Backeddy Books. p. 281. ISBN 0-9603566-3-0.
  3. ^ Rand McNally and Company, Road map: Idaho, Mont., Wyo., published by Texaco, 1937