US 87 in Wyoming

US 87 in Wyoming


US 87
Get started Cheyenne
End Ranchester
Length 351 mi
Length 565 km
  • Colorado
  • Colorado – Glenrock
  • Glenrock
  • Casper
  • Casper-Montana:
  • Montana

According to Indexdotcom, US 87 is a US Highway in the US state of Wyoming. The road forms a north-south route through the eastern half of the state and is double-numbered along its entire route with Interstate 25, Interstate 90, and a portion of US 20 / US 26.

Travel directions

see: Interstate 25 in Wyoming and Interstate 90 in Wyoming for the main topic.

US 87 follows Interstate 25 from the Colorado border to Glenrock. This section heads north through the state capital Cheyenne, where it crosses Interstate 80, then across the High Plains to Glendo, where I-25 branches west. Just before Glenrock, US 87 leaves I-25, after which it parallels I-25 along with US 20 and US 26 westwards to Casper.

From Casper, US 87 follows I-25 again, this route heads north to the end of I-25 at Buffalo, after which US 87 becomes Interstate 90. Near Story, US 87 then exits I-90 and forms an individual route for the first time in Wyoming that is not double-numbered with other major roads. US 87 runs along the base of the Bighorn Mountains, parallel to I-90 to the town of Sheridan. From Sheridan, US 87 rejoins I-90 to the border with Montana.


US 87 was one of the original US Highways of 1926. US 87 then went further west in southern Wyoming, the starting point was US 30 in Rawlins at the time. At the same time, US 185 between Cheyenne and Orin also existed. In 1936, US 87 was modified and extended to Port Lavaca, Texas. In Wyoming, US 87 no longer ran via Rawlins, but from Casper east to Orin with a double number with US 20 and US 26, and from there south over the former US 185 to the border with Colorado south of Cheyenne.

Originally, there was also a large-scale bifurcation of US 87 into an east and west route, between Muddy Gap, Wyoming and Great Falls, Montana. The US 87E followed the route via Casper and Sheridan to Great Falls, this route was 925 kilometers long. US 87W followed a more westerly route through Yellowstone National Park and Livingston, Montana, a 900-kilometer route. The route of the US 87W actually fitted better into the grid of the US Highways than the later route via Sheridan. This split was changed in 1936 when US 87W was dropped and US 87E became the main route. US 87E existed between Muddy Gap and Casper until 1939, when it became State Route 220.

The entire route of US 87 has been replaced by Interstate Highways, namely I-25 between Cheyenne and Buffalo and I-90 between Buffalo and the border with Montana. These motorways were opened to traffic in phases between 1958 and 1985. US 87 continued to run on only two short stretches separate from I-25 and I-90, along with US 20/26 between Glenrock and Casper and further north as an individual route between Story and Sheridan. This 16-mile stretch is the only portion of US 87 in Wyoming that is not double-numbered with other US Highways or Interstate Highways.

Traffic intensities

Every day, 1,000 to 3,000 vehicles travel over the double numbering with US 20/26 between Glenrock and Casper and 1,500 to 5,000 vehicles between Story and Casper.

Mountain Passes in Wyoming

The Beartooth Pass.

This is an overview of mountain passes in Wyoming above 2,000 feet.


Mountain passes in Wyoming are not clearly linked to one mountain range, but most are located in the northwest part of the state, in and around Yellowstone National Park. Wyoming does not have one clear main chain of the Rocky Mountains, but also consists of clustered mountain areas with lower elevations surrounding them. All the high mountain passes in this list are paved and most are also kept open in the winter because Wyoming has a very thin road network and alternative routes are often not available. A number of mountain passes have primarily a tourist function, including the highest, Beartooth Pass. This is also the most difficult mountain pass to drive along with the Dead Indian Pass which is located in the same region.

Wyoming is sparsely populated and the small towns that exist are far apart. Most mountain passes are therefore very light, often less than 1,000 vehicles per day, and sometimes less than 400 vehicles per day. The quietest high pass is the Battle Pass. Due to the low population density, the road network is very thin and there are therefore few mountain passes for a large area like Wyoming. There are 3 mountain passes of more than 3,000 meters altitude. The list does not include freeways, despite the fact that Interstate 80 in Wyoming in particular runs above 2,000 meters in various places. Technically, these are not mountain passes. I-80 is built over the most direct route, rather than the lowest route as is the case with mountain passes.


Most of the mountain passes were discovered by expeditions in the early 19th century. Unlike in Colorado, there are hardly any railroads built over the mountain passes in Wyoming. By far the easiest pass is the South Pass. Most passes around Yellowstone National Park are the oldest, this is the oldest tourist area in the United States.


Mountain pass Route Height (m)
Beartooth Pass 3337
Snowy Range Pass 3315
Battle Pass 3034
Powder River Pass 2945
Togwotee Pass 2943
Granite Pass 2754
Dunraven Pass 2695
Sherman Hill Summit 2633
Sylvan Pass 2598
Teton Pass 2571
Craig Pass 2537
Dead Indian Pass 2400
South Pass 2304
Kingman Pass 2170

US 87 in Wyoming