Muddy Pass

Muddy Pass is a Continental Divide crossing on U.S. 40 in northern Colorado, summit elevation 8,772 ft, right on the line between Jackson and Grand counties. It sits in the gap between the Park Range to the north and the Rabbit Ears Range to the east. US-40 carries traffic over it between Kremmling and Steamboat Springs. As Continental Divide crossings go in this state, it is one of the lowest you can drive. Wikipedia describes it as rarely closed in winter, with a mild approach on both sides and no switchbacks or tight spots.

For a trucker, Muddy Pass is the easy half of a paired climb. Westbound, US-40 tops Muddy Pass first. About 3 miles further west it crosses the higher Rabbit Ears Pass at 9,426 ft. Then the real work begins: the steep drop into Steamboat Springs. Rabbit Ears is roughly 500 ft higher than Muddy, and it is the harder of the two. So when people talk about "the pass" on this stretch, the grade and the curves and the runaway ramp all belong to Rabbit Ears, not to Muddy.

The hard part is the western descent off Rabbit Ears toward Steamboat. That side runs a 6.8% grade that drops about 3,000 ft over roughly 7 miles, with sharp curves, ranked the 28th steepest pass in Colorado. The eastern side toward Muddy Pass is far gentler. Wikipedia notes US-40 descends along a slow incline on that side. Live pass status, chain-law activations, the brake-check and chain stations, and cameras all come from CDOT at COtrip (maps.cotrip.org), which lists dedicated US-40 Rabbit Ears Pass Chain Station/Brake Check points for both eastbound and westbound traffic.

• Muddy Pass summits at 8,772 ft (2,674 m) on the Continental Divide, on the Jackson/Grand county line (Wikipedia, Muddy Pass).
• Rabbit Ears Pass, about 3 miles west, is roughly 500 ft higher at about 9,426 ft and is the steeper, harder crossing (Wikipedia; Uncover Colorado).
• The west descent off Rabbit Ears into Steamboat is a 6.8% grade dropping about 3,000 ft over roughly 7 miles, 28th steepest pass in Colorado (Wikipedia, Rabbit Ears Pass; crashforensics.com).
• One runaway truck ramp sits on US-40 westbound near milepost 142 (Wikipedia, Rabbit Ears Pass; crashforensics.com).
• Commercial chain law: vehicles over 16,000 lb GVWR must carry chains or approved traction devices Sept 1 to May 31 from MP 256 (Empire) to the Utah border, which includes this segment (CDOT Freight; CDLLife).
• Steamboat Springs is about 24 miles west; Kremmling is roughly 30 minutes south (Uncover Colorado).
• US-40 over Muddy Pass is plowed and open year-round; Wikipedia notes it is rarely closed in winter (Wikipedia).

Colorado's Commercial Vehicle Chain Law runs September 1 through May 31. On US-40 from milepost 256 (Empire) to the Utah border, which covers the Muddy/Rabbit Ears segment, any commercial vehicle over 16,000 lb GVWR (or carrying 16 or more passengers) must carry chains or approved alternate traction devices during that window, no matter what the weather is doing that day. When CDOT actually activates the chain law, single-drive-axle and tandem-drive combinations chain 4 drive tires (Level 1); buses and lighter combos chain 2 (Level 2). The named control point is CDOT's US-40 Rabbit Ears Pass Chain Station/Brake Check, listed separately for eastbound and westbound on COtrip. CDOT and local reporting put the active commercial chain-law segment on US-40 between mileposts 136 and 154, and the Muddy Pass summit falls inside it.

There is no fixed seasonal closure. The road is kept open all year, and closures are event-driven, not scheduled. Two things shut it down. The first is a severe winter storm with heavy snow, drifting, and whiteout (northern passes like Rabbit Ears can pick up as much as two feet of snow in one system). The second is a crash, especially a jackknifed or disabled truck on the steep west grade that blocks one or both directions until removal. CDOT has scheduled full closures of Rabbit Ears specifically to pull stuck commercial vehicles (one planned US-40 closure for CMV removal, CDOT news, Oct 2022), and the Colorado State Patrol has posted full closures of Highway 40 from about MP 139 through MP 158 during storms. There is no published hard mileage or duration rule. Status is dynamic and announced through COtrip, the CDOT app, and @ColoradoDOT.

Muddy Pass was on the route of John C. Frémont's expedition. In June 1844 his party came down out of North Park and crossed south over Muddy Pass, near where US-40 and CO-14 meet today, on its return through northwest Colorado. The pass takes its name from nearby Muddy Creek, whose water runs into the Colorado River near Kremmling. The adjacent Rabbit Ears Pass road that completes the US-40 crossing was a major early-1900s engineering job. Construction started in 1911 and was not finished until 1917. Rabbit Ears Pass, and by extension the crossing, is named for nearby Rabbit Ears Peak in the Park Range. Early trappers used the distinctive rock formation as a landmark for the approach into the Yampa Valley.

The divide crossing itself is now hard to spot on the ground. A Continental Divide sign once stood at the Muddy Pass summit (photographed in 2014, visible in 2012 Street View), but it had been removed by 2021, so the line is largely unmarked today.