Sherman Summit

Sherman Summit sits on the crest of the Laramie Mountains in Albany County, Wyoming, on I-80 between Cheyenne and Laramie. It is about 9 miles east of Laramie and 36 miles west of Cheyenne, near Exit 323. At 8,640 ft, this is the highest point on Interstate 80 across the whole transcontinental route. A WYDOT sign at the rest area says so flat out: "Highest Point on Interstate 80. Elev 8640." Buford, just west of the summit at about 8,000 ft, is the highest community on I-80.

One thing to get straight. It is not the highest point on the entire Interstate Highway System. That belongs to the Eisenhower-Johnson Memorial Tunnel on I-70 in Colorado at 11,158 ft. Sherman Summit comes in second. What makes this corridor hard is not the altitude alone. WYDOT describes the Summit/Telephone Canyon stretch as average grades of about 6% with long winding curves, and variable speed-limit signs are posted throughout and have to be followed.

The wind is the real story here. This corridor is known for gusts that can blow loaded trucks and trailers onto their sides or off the road. Snow falls even into early summer because of the 8,000-plus-ft elevation. The 77-mile run over and west of the summit, from Laramie to Walcott Junction, earned the nickname "Snow Chi Minh Trail" for its ground blizzards. At the Summit Rest Area you will pass a 12.5-ft bronze bust of Abraham Lincoln on a 30-ft granite pedestal, a landmark for drivers cresting the hill.

• Highest point on all of I-80 at 8,640 ft, but second-highest on the Interstate system behind the Eisenhower-Johnson Tunnel at 11,158 ft (Wikipedia; CDOT).
• Near Exit 323, about 9 miles east of Laramie and 36 miles west of Cheyenne (Wikipedia; Anne's Travels).
• WYDOT cites average grades of about 6% with long winding curves through the Summit/Telephone Canyon section; variable speed-limit signs are mandatory (WHP Mountain Road Information).
• Buford, just west of the summit at about 8,000 ft, is the highest community on I-80 (AARoads).
• The 77-mile Laramie-to-Walcott-Junction segment is nicknamed the 'Snow Chi Minh Trail' for its ground blizzards (Wikipedia).
• Gusts here frequently exceed 60 mph and have reached 100 mph, strong enough to flip trucks (WHP; FHWA cs101).
• A 12.5-ft bronze Lincoln bust on a 30-ft granite pedestal stands at the Summit Rest Area (Wikipedia; Cowboy State Daily).

Wyoming has no fixed chain-law season. WYDOT activates restrictions by conditions, not the calendar, with the practical window running October through April. There are two levels. Level 1 (conditions hazardous) restricts travel to vehicles with tire chains, adequate snow tires, or all-wheel drive. Level 2 (extremely hazardous) restricts travel to vehicles with tire chains, or AWD with adequate mud/snow or all-weather tires; commercial vehicles must chain at least two drive wheels at opposite ends of the same drive axle. Fines run $250 for violating the restriction and $750 if your violation causes a highway closure. On I-80 the Summit/Telephone Canyon segment around MP 318 is a regular activation point, along with the "Three Sisters" at MP 7-34 west of Cheyenne and Walcott Junction at MP 235. Wyoming does not use formally named chain-up areas the way Western Slope states do. Troopers run compliance checks at designated pull-outs.

There is no published wind-speed number at which I-80 auto-closes here. WYDOT closes by judgment during winter storms and high-wind or ground-blizzard events. Two modes happen. First, wind and blow-over events can shut the road with little or no falling snow when gusts pick up ground snow into whiteouts and topple high-profile trucks; WYDOT may restrict or close the road to light and high-profile vehicles. Second, full storm closures can shut long stretches, often Cheyenne to Rock Springs (200-plus miles), to all through traffic for hours to days. Closures come fast and can last a while. The May 18, 2026 blizzard closed both directions between Rock Springs and Cheyenne by 10:46 a.m. and stranded motorists overnight. Subscribe to per-segment closure, chain-law, and blow-over alerts at wyoroad.info.

The last major section of I-80 in Wyoming opened on Saturday, October 3, 1970. Four days later a snowstorm shut it down. Within three months the 77-mile Laramie-to-Walcott-Junction stretch was buried by 16-ft drifts in 27 places and closed for 10 days straight, with winds up to 100 mph and near-zero visibility. Those first brutal winters earned the road its nickname, the "Snow Chi Minh Trail," likening the conditions to the North Vietnamese supply route. The Wyoming State Historical Society published a 2017 book of that title. The disaster pushed Wyoming to pioneer modern highway snow fencing. WYDOT put up 11.4 miles of fence at the 27 worst sites in 1971, expanding to about 40 miles along this part of I-80. Statewide the system has since grown to hundreds of miles, cutting snow-removal costs and reducing blowing-snow accidents by about 70%.

The big Lincoln you see at the top of the hill has its own history. The Abraham Lincoln Memorial Monument, a 12.5-ft bronze bust on a 30-ft granite pedestal by University of Wyoming sculptor Robert Russin, was dedicated in 1959 for Lincoln's 150th birthday. It first stood on Sherman Hill overlooking the old Lincoln Highway/US 30, then moved to the I-80 Summit Rest Area in 1969 once the interstate was finished. It was cast in Mexico City over about 11 months and financed by Dr. Charles W. Jeffrey of Rawlins.