Wyoming Highway 89 is a north-south state road that jumps in and out of Wyoming three times, and runs through the western edges of and Uinta County, Wyoming and Lincoln County, Wyoming.

Wyoming Highway 89 has two different segments to its route. The first starts at I-80/US 189 (Exit 5) and Wyoming Highway 150 in Evanston. (The roadway continues south of I-80/US 189 as WYO 150 to the Utah border). From Exit 5, WYO 89 heads north as Front Street into downtown Evanston. At 0.44 miles (0.71 km), Highway 89 turns north onto Highway 89 north. From here, WYO 89 runs concurrent for a short distance with I-80 Business/US 189 Business until it intersects Bear River Drive where the business routes turn east. As Highway 89 leaves Evanston behind the roadway heads northwest. The highway passes through the former coal mining camp of Almy and reaches the Town of Bear River just before reaching the Utah state line. Bear River is one of Wyoming's newest towns, being incorporated in 2001. Just after leaving Bear River, WYO 89 temporarily ends at Utah State Route 16.

The roadway continues as Utah SR-16. SR 16 intersects Utah SR-39 in Woodruff, Utah at 10.51 miles (16.91 km) from its start at WYO 89. Utah SR-16 ends at Utah SR-30 in Sage Creek Junction, Utah at 29.36 miles (47.25 km). Utah SR-30 'East' takes you back to the Utah-Wyoming State Line, where at 33.00 miles (53.11 km), SR-30 ends and WYO 89 resumes.

The northern segment of Wyoming Highway 89 begins at Utah State Route 30 at the Utah-Wyoming state line west of Sage, Wyoming. WYO 89 travels northeast to US 30 at Sage. Here, WYO 89 turns north to join US 30 as it heads north

WYO 89 runs concurrent with US 30 for almost 30 miles (48 km) from Sage through Cokeville, north to one-half mile east of the Idaho-Wyoming state line. This section is also known as the Emigrant Trail. At 36.11 miles (58.11 km), US 30/WYO 89 intersects WYO 231 (E. Main St.) and WYO 232 in the Town of Cokeville. From there WYO 89 continues with US 30 north. At 46.51 miles (74.85 km), WYO 89 ends its concurrency with US 30 near Border, Idaho.

Wyoming Highway 89 heads north from U.S. Route 30 as it continues westward. WYO 89 then travels north for approximately 10 miles (16 km), closely paralleling the Idaho-Wyoming state line until it finally crosses it and finally ends near Geneva, Idaho.

Wyoming Highway 89 ends but the roadway continues as Idaho State Highway 61 for a very short length of 0.8 miles (1.3 km), until it ends at US 89 in Geneva, Idaho.

According to an original network map of Wyoming State Highways in 1924, this route was defined as Wyoming Highway 65. With the introduction of US routes in 1926, the route between Cokeville and Star Valley was renamed Wyoming Highway 89, while the section south of Sage remained designated as WYO 65. This was done in the hopes that US 89 would be extended north into Wyoming. US 89 was extended in 1936 along old Wyoming 287. Wyoming Highway 89 was recommissioned as Wyoming Highway 91 to avoid confusion between the two highways, while Highway 65 kept its original number. However, within a few years, US 89 was rerouted to its current route in Utah and Idaho, and US 189 was created along old Wyoming 287. As a result, Wyoming recommissioned Wyoming Highway 89 over both WYO 65 and WYO 91.