.svg) .svg)  Signage for Interstate 80, Interstate 180, and Interstate 80 Business | |
 Interstate Highways highlighted in red | |
| Highway names | |
|---|---|
| Interstates | Interstate X (I-X) |
| Business routes: | Interstate X Business (I-X Bus.) |
| System links | |
| |
TheInterstate Highways in Wyoming are the segments of theDwight D. Eisenhower National System of Interstate and Defense Highways owed and maintained by theWyoming Department of Transportation. It comprises 914 miles (1,471 km) on four routes as well asBusiness Interstate Highways. Construction began in September 1956 onInterstate 25 (I-25) and the network was completed in October 1985.[1] It cost an estimated $570 million to build Wyoming's portion of the Interstate Highway System.[2]
| Number | Length (mi) | Length (km) | Southern or western terminus | Northern or eastern terminus | Formed | Removed | Notes | |
|---|---|---|---|---|---|---|---|---|
 I-25 | 300.53 | 483.66 | I-25 /US 87 at theColorado state line towardsDenver | I-90 /US 87 atBuffalo, Wyoming with passageways toBillings, Montana andRapid City, South Dakota | 01956-01-011956 | current | Runs concurrently withUS 87 almost entirely in the state | |
 I-80 | 402.78 | 648.21 | I-80 /US 189 at theUtah state line towardsSalt Lake City | I-80 at theNebraska state line towardsOgallala | 01956-01-011956 | current | Longest interstate in Wyoming; also known as the Lincoln Highway | |
 I-90 | 208.80 | 336.03 | I-90 /US 87 at theMontana state line towardsBillings | I-90 /US 14 at theSouth Dakota state line towardsRapid City | 01956-01-011956 | current | Only Interstate that does not serveCheyenne | |
 I-180 | 1.09 | 1.75 | I-80 inCheyenne | I-80 Bus. /US 30 inCheyenne | 01984-01-011984 | current | Highway not up toInterstate Highway standards; runs concurrently withI-25 Business,US 85, and US 87 Business in its entire length; also the only auxiliary route in Wyoming | |
| Number | Length (mi) | Length (km) | Southern or western terminus | Northern or eastern terminus | Formed | Removed | Notes | |
|---|---|---|---|---|---|---|---|---|
 I-25 BL | 8.006 | 12.884 | I-25/US 87 inCheyenne | I-25/US 87 in Cheyenne | — | — | Runs entirely concurrently with US 87 Business; also runs concurrently withI-180 andUS 85 entering Cheyenne | |
| I-25 BL | 3.28 | 5.28 | I-25/US 87 andWYO 211 inChugwater | I-25/US 87 andWYO 321 northeast of Chugwater | — | — | Entirely concurrent withWYO 313 andWYO 321 | |
| I-25 BL | 4.966 | 7.992 | I-25/US 87 inDouglas | I-25/US 87 southeast of Douglas | — | — | Entirely concurrent withUS 20 Business, US 26 Business, and US 87 Business | |
| I-25 BL | 6.98 | 11.23 | I-25/US 87 southwest ofGlenrock | I-25/US 20/US 26/US 87 southeast of Glenrock | — | — | Runs concurrently with County Road 19 entering Glenrock and then US 20 and US 26 heading east of Glenrock | |
| I-25 BL | 2.180 | 3.508 | I-25/US 87 inCasper | I-25/US 20/US 26/US 87 east of Casper | — | — | Unsigned; entirely concurrent with US 87 Business; also runs concurrently with unsignedWYO 255, US 20, and US 26 | |
| I-25 BL | 1.673 | 2.692 | I-25/US 87 south ofBuffalo | I-90/US 87 north of Buffalo | — | — | Entirely concurrent with US 87 Business; also runs concurrently withI-90 Business andWYO 196 | |
 I-80 BL | 3.150 | 5.069 | I-80/US 189 west ofEvanston | I-80/US 189 east of Evanston | — | — | Entirely concurrent with US 189 Business; also runs concurrently withWYO 89 | |
| I-80 BL | 15.630 | 25.154 | I-80 west ofFort Bridger | I-80 east ofLyman | — | — | Longest Interstate business route in Wyoming; also the only business route in Wyoming not concurrent with another route | |
| I-80 BL | 2.5 | 4.0 | I-80/US 30 northwest ofGreen River | I-80/US 30 east of Green River | — | — | Entirely concurrent withUS 30 Business; also runs concurrently withWYO 374 | |
| I-80 BL | 4.120 | 6.630 | I-80/US 30/US 191 west ofRock Springs | I-80/US 30 northeast of Rock Springs | — | — | Entirely concurrent withUS 30 Business | |
| I-80 BL | 3.770 | 6.067 | I-80/US 30 west ofRawlins | I-80/US 30/US 287 | — | — | Entirely concurrent withUS 30 Business; also runs concurrently with US 287 | |
| I-80 BL | 6.357 | 10.231 | I-80 inLaramie | I-80/US 30 east of Laramie | — | — | Runs concurrently with US 30, US 287, and County Road 322 north of Laramie | |
| I-80 BL | 6.935 | 11.161 | I-80 west of Cheyenne | I-80/US 30 east of Cheyenne | — | — | Entirely concurrent with US 30 | |
 I-90 BL | 5.4 | 8.7 | I-90/US 14/US 87 north ofSheridan | I-90 southeast of Sheridan | — | — | Entirely concurrent with US 14; also runs concurrently with US 87 | |
| I-90 BL | 2.2 | 3.5 | I-90/US 87 north of Buffalo | I-90 east of Buffalo | — | — | Runs concurrently withI-25 Business, WYO 196, US 87 Business, and thenUS 16 | |
| I-90 BL | 3.3 | 5.3 | I-90 west ofGillette | I-90/US 14/US 16 east of Gillette | — | — | Runs concurrently with US 14 and US 16 almost in its entire length; also runs concurrently withWYO 50 andWYO 59 | |
| I-90 BL | 1.6 | 2.6 | I-90 northwest ofMoorcroft | I-90 in Moorcroft | — | — | Unsigned; runs concurrently with US 14 and US 16 entering Moorcroft | |
| I-90 BL | 3.4 | 5.5 | I-90 southwest ofSundance | I-90 east of Sundance | — | — | Entirely concurrent with US 14 | |
Media related toInterstate Highways in Wyoming at Wikimedia Commons