Cimarron County is the westernmost county in the U.S. state of Oklahoma. Its county seat is Boise City. As of the 2020 census, its population was 2,296, making it the least-populous county in Oklahoma; and indeed, throughout most of its history, it has had both the smallest population and the lowest population density of any county in Oklahoma. Located in the Oklahoma Panhandle, Cimarron County contains the only community in the state (Kenton) that observes the Mountain Time Zone. Black Mesa, the highest point in the state, is in the northwest corner of the county. The Cimarron County community of Regnier has the distinction of being the driest spot in Oklahoma ranked by lowest annual average precipitation, at just 15.62 inches; at the same time, Boise City is the snowiest location in Oklahoma ranked by highest annual average snowfall, at 31.6 inches.
U.S. Route 412 is an east–west United States highway, first commissioned in 1982. U.S. 412 overlaps expressway-grade Cimarron Turnpike from Tulsa west to Interstate 35 and the Cherokee Turnpike from 5 miles (8.0 km) east of Chouteau, Oklahoma, to 8 miles (13 km) west of the Arkansas state line. It runs the entire length of the Oklahoma Panhandle and traverses the Missouri Bootheel.
U.S. Route 287 (US 287) is a north–south United States highway. At 1,791 miles (2,882 km) long, it is the second longest three-digit U.S. Route, behind US 281. It serves as the major truck route between Dallas-Fort Worth and Amarillo, Texas, and between Fort Collins, Colorado, and Laramie, Wyoming. The highway is broken into two segments by Yellowstone National Park, where unnumbered park roads serve as a connector.
U.S. Route 56 is an east–west United States highway that runs for approximately 640 miles (1,030 km) in the Midwestern United States. US 56's western terminus is at Interstate 25 Business, US 412 and New Mexico State Road 21 in Springer, New Mexico and the highway's eastern terminus is at US 71 in Kansas City, Missouri. Much of it follows the Santa Fe Trail.
U.S. Route 177 (US-177) is a spur of U.S. Route 77. It currently runs for 233 miles (375 km) from South Haven, Kansas at US-81 to Madill, Oklahoma at US-70. It passes through the states of Kansas and Oklahoma.
U.S. Route 385 (US 385) is a spur of U.S. Route 85 that runs for 1,206 miles (1,941 km) from Deadwood, South Dakota to Big Bend National Park in Texas.
State Highway 99 (SH-99) is a north–south state highway through central Oklahoma. It runs from the Texas state line at Lake Texoma to the Kansas state line near Lake Hulah. It is 241.5 miles (388.7 km) long. The highway overlaps U.S. Highway 377 (US-377) for over half its length.
State Highway 3, also abbreviated as SH-3 or OK-3, is a highway maintained by the U.S. state of Oklahoma. Traveling diagonally through Oklahoma, from the Panhandle to the far southeastern corner of the state, SH-3 is the longest state highway in the Oklahoma road system, at a total length of 615 miles (990 km) via SH-3E.
State Highway 325, officially, SH-325, is a state highway in the U.S. state of Oklahoma. SH-325 runs for 38.08 miles (61.28 km) through Cimarron County, Oklahoma, from a continuation of New Mexico State Road 456 at the New Mexico border west of Kenton to the traffic circle in Boise City. Along the way it provides access to Black Mesa State Park, near Black Mesa, the highest point in the state of Oklahoma.
State Highway 171, abbreviated as SH-171, is a state highway in Cimarron County, Oklahoma, in the Oklahoma Panhandle. It runs for 21.47 miles (34.55 km) north and south through the eastern part of the county, connecting U.S. Highway 287 near the Oklahoma-Texas state line to US-56 in Keyes. The only other highway it intersects with is US-64/412/SH-3, three miles (5 km) south of Keyes. SH-171 has no lettered spur routes.
U.S. Highway 287 (US 287) in the U.S. state of Texas is a major U.S. Highway that begins on the Gulf Coast in Port Arthur and heads north through Fort Worth, northwest to Childress, Clarendon, Wichita Falls, and Amarillo in the Texas Panhandle and into Oklahoma near Kerrick.
U.S. Highway 60 in Texas is a 210.70-mile-long U.S. Highway that runs southwest to northeast through the Texas Panhandle. The route passes through the cities of Hereford, Canyon, Amarillo, and Canadian.
U.S. Route 54 in Texas is a U.S. Highway that travels through two portions of the state: one in the far western point, and the other in the far northwest Panhandle.
State Highway 95 is a state highway in the Panhandle region of the U.S. state of Oklahoma. This route, which is 42.1 miles (67.8 km) long, runs entirely through western Texas County. SH-95 does not have any lettered spur routes.
U.S. Highway 385 (US 385), also known as the High Plains Highway north of Cheyenne Wells, is the easternmost significant north–south state highway in the U.S. state of Colorado, and many of the state's major east–west routes intersect with US 385 before crossing into neighboring Kansas and Nebraska. It enters the state from Oklahoma while overlapped with US 287, but splits at Lamar to follow its own route through the Eastern Plains to Nebraska.
U.S. Route 412 is a U.S. highway in the south-central portion of the United States, connecting Springer, New Mexico to Columbia, Tennessee. A 504.11-mile (811.29 km) section of the highway crosses the state of Oklahoma, traversing the state from west to east. Entering the state southwest of Boise City, US-412 runs the length of the Oklahoma Panhandle and serves the northern portion of the state's main body, before leaving the state at West Siloam Springs. Along the way, the route serves many notable cities and towns, including Boise City, Guymon, Woodward, Enid, and the state's second-largest city, Tulsa.
U.S. Route 64 (US-64) is a U.S. highway running from the Four Corners area to the Outer Banks of North Carolina. Between these two points, the highway passes through the entire width of Oklahoma; a total of 591.17 miles (951.40 km) of US-64 lies in the state of Oklahoma. US-64 enters the state from New Mexico, crossing the line between the two states between Clayton, New Mexico, and Boise City in Cimarron County. The route runs the full length of the Oklahoma Panhandle, then serves the northernmost tier of counties in the main body of the state before dipping southeastward to Tulsa, the state's second-largest city. From Tulsa, the highway continues southeast, leaving Oklahoma just west of Fort Smith, Arkansas. In addition to Tulsa, US-64 serves fifteen Oklahoma counties and the cities of Guymon, Woodward, Enid, and Muskogee.
The Cimarron County Courthouse is the historic courthouse serving Cimarron County, Oklahoma, located in Boise City. The courthouse was designed by M.C. Parker in the Classical Revival and Neoclassical styles and built in red brick by Strong & Froman. The building opened in 1926 after the previous wood-frame courthouse burned down. The courthouse is surrounded by a traffic circle that has several highways in a unique example of concurrency, including US-56, US-64, US-287, US-385, US-412, State Highway 3, and SH-325. The highways lead to different locations including north to Colorado, northeast to Kansas, west to New Mexico, and southwest to the Texas Panhandle. On August 23, 1984, the courthouse was added to the National Register of Historic Places.
U.S. Highway 287 is the portion of a north-south highway in Colorado that travels from the Oklahoma state line just south of Campo to the Wyoming state line north of Fort Collins.
U.S. Route 70 (US 70) is a U.S. Highway that spans from Globe, Arizona to Atlantic, North Carolina. In Texas, it has a portion that begins at the New Mexico state line in Farwell and ends at the Oklahoma state line northeast of Oklaunion.
US 287 at the Texas state line
US 56 / US 64 / US 412 in Boise City 
US 385 in Boise City 
