South Pass

South Pass is the broad saddle where Wyoming Highway 28 crosses the Continental Divide at 7,550 ft. Despite the prompt's framing, the summit is not on US-287. WY-28, the South Pass Highway, is the road that climbs over the pass. It meets US-287/WY-789 about 8 miles south of Lander at its east end, so US-287 is the connection, not the crossing. The original Oregon Trail pass about 2.5 miles to the southeast sits a little lower at 7,412 ft. This is one of the lowest crossings on the Continental Divide, a gentle approach rather than a steep alpine notch. The BLM describes it as an almost imperceptible approach to the divide, an easy grade to and through the mountains.

For truckers, WY-28 is the diagonal shortcut. It is 96.4 miles, two-lane its whole length, maintained by WYDOT. It runs from a split with WY-372 in Sweetwater County, past Farson at US-191, across the high plains and over the pass, then down past Red Canyon to the US-287/WY-789 junction near Lander. That line links the I-80 corridor and US-191 (Pinedale, Rock Springs area) to Lander, Riverton and central Wyoming without a long detour. The Wyoming Highway Patrol flags the route for long, steep grades and severe weather.

What makes this pass tricky is not a knife-edge climb. It is the wind and the remoteness. The road closes to light and high-profile vehicles for dangerous winds, sometimes in summer, and it shuts to all travel in winter whiteouts. There are no services for long distances, and help can take a long time to arrive. WHP also notes wildlife is a hazard along most of the highway. Check WYDOT 511 before you commit a load to it.

• Summit elevation where WY-28 crosses: 7,550 ft; the original Oregon Trail pass nearby is 7,412 ft (Wikipedia, BLM)
• WY-28 is 96.4 miles, two-lane its entire length, maintained by WYDOT (Wikipedia)
• South Pass is one of the lowest crossings on the Continental Divide, a broad gentle saddle (BLM)
• The pass is on WY-28, not US-287; WY-28 meets US-287/WY-789 about 8 miles south of Lander (Wikipedia, AARoads)
• Level 2 chain law has been enforced here, documented Feb. 7, 2025 (County 10)
• Wind closures set a moving GVW cutoff per storm, from 20,000 up to 50,000 GVW in 2025 (County 10)
• Chain law fines run up to $250, or $750 if the violation causes a highway closure (WYDOT Chain Law)

There is no fixed chain-control calendar on South Pass. Chain law is activated by conditions, not by date. The Wyoming Highway Patrol says wintry conditions here run from late fall through early spring, and sometimes even in the summer months. So the season is roughly late fall to early spring, but it can open and close many times in a single winter and even bite off-season for wind. Chain restrictions and closures lift when conditions clear, which can be hours or, as the notices often say, an unknown estimated reopening. Check WYDOT 511 at wyoroad.info, the Wyoming 511 app, or dial 511 for the current status before you climb.

Long before it was a highway, South Pass was the easy way over the Continental Divide. Robert Stuart and the returning Astorians made the first documented crossing by white men in October 1812. In 1832 Capt. Benjamin Bonneville brought the first wagons over, a caravan of 110 men and 20 wagons. On July 3, 1836, Narcissa Whitman and Eliza Hart Spalding crossed here and became the first white women to cross the Continental Divide. Between 1841 and 1869, somewhere between roughly 350,000 and 500,000 emigrants used South Pass on the Oregon, California and Mormon trails before the transcontinental railroad opened (WyoHistory.org).

The pass stayed a corridor for fast traffic too. The Pony Express ran through it in the spring of 1860, carrying mail Missouri to California in about two weeks, and the transcontinental telegraph was completed along the route in the fall of 1861. The historic South Pass area was designated a National Historic Landmark on Jan. 20, 1961 (this date is Wikipedia-sourced).