Mudslides buried Colorado’s Highway 133 and cut off the road to Maroon Bells

Mudslides shut down both Highway 133 and Maroon Creek Road in Pitkin County, Colorado, within hours of each other on September 14, burying stretches of pavement in rock and debris and cutting off the only paved route into the Maroon Bells-Snowmass Wilderness. Highway 133 closed in both directions from Mile Marker 47 to Mile Marker 54 by 5 p.m. that evening after multiple slides hit the road near Redstone, while Maroon Creek Road closed separately at its 7-mile mark. No injuries were reported in either slide, and neither closure came with an estimated reopening time.

The two roads share a canyon but not a single cause. Garfield County officials, who manage the northern stretch of Highway 133, did not specify what triggered a downed power line that briefly closed the road near Roaring Fork High School earlier that same morning. Pitkin County officials, farther south, told the Aspen Daily News the Maroon Creek Road slide was caused by heavy rain, and a second mudslide struck Highway 133 again that afternoon at Mile Marker 53, near the north Redstone entrance.

Pitkin County crews already knew this stretch of canyon well

The corridor was not new to mudslides. A mudslide blocked both lanes of Highway 133 about six miles north of Redstone in July 2025, burying the road in a slide roughly 35 feet long and two to three feet deep while Colorado Department of Transportation crews worked to clear it. Parker Lathrop, chief deputy of operations at the Pitkin County Sheriff’s Office, said at the time that slides are common on that stretch during rainy days “due to the elevation and unstable terrain surrounding the highway.”

The terrain did not change between 2025 and the September 2026 closures, and Aspen Public Radio’s rolling coverage of the newer slides described the same pattern: a short, intense burst of rain, a canyon wall that cannot hold it, and a highway with nowhere to route around the debris. County crews responded to the September 2026 slides using the same emergency-alert system, PitkinAlert, that carried word of the 2025 closure to residents and drivers.

The National Weather Service tied the slides to a specific flash flood warning

The National Weather Service issued a flash flood warning for northwestern Pitkin County that ran through at least 7:15 p.m. on September 14, stating that Highway 133 is prone to rockslides and mudslides during heavy rain and that radar was showing a storm capable of producing life-threatening flash flooding of creeks, streams, urban areas, highways and underpasses that evening. The agency’s standing advice for any driver who meets a flooded road is to turn around rather than attempt a crossing, since most flood deaths in the United States happen inside vehicles rather than outdoors, often because the depth of water covering a road is impossible to judge from the driver’s seat.

That warning arrived as the mudslides were already active, not ahead of them, which limited how much advance notice either county could give drivers already on Highway 133 or Maroon Creek Road. Rain continued through the evening, and the National Weather Service was forecasting more of it through the rest of that week.

Maroon Creek Road’s closure reached past the highway into the wilderness itself

Maroon Creek Road is the only paved entrance to the Maroon Bells-Snowmass Wilderness Area, home to the twin 14,000-foot peaks that make the Maroon Bells one of Colorado’s most photographed landmarks, so its closure reached past commuters and directly into the tourist season. White River National Forest officials told the Aspen Daily News on September 14 that the hiking and camping area would stay closed for at least the rest of that day, and by that evening the Forest Service confirmed the road would remain shut to both vehicles and bicycles through the following day as well.

The Maroon Bells RFTA shuttle kept running its normal schedule starting at 7 a.m. the next morning regardless, and visitors holding a paid parking reservation for that day were given free shuttle access for up to two people per pass, with additional riders paying the standard per-person fare. Forest officials also reported new debris flows elsewhere in the wilderness, including along the Four Pass Loop, and reminded hikers that the backcountry trails themselves stayed open despite the road closure, with visitors responsible for their own safety in the meantime.

Both roads reopened within two days, but new slides kept returning

Highway 133 reopened in both directions by 8:45 p.m. on September 14, though emergency officials continued warning drivers about mud still sitting on the roadway. The relief did not last: the highway closed again the following morning near Mile Marker 49.5, at Hayes Creek Falls, after multiple new mudslides hit the same general stretch. Pitkin County officials said at the time that they did not know how long the second closure would last, and the highway did not reopen again until roughly 11:30 a.m. that Tuesday.

Maroon Creek Road took slightly longer, reopening around 10 p.m. that Tuesday with debris still visible on the pavement and officials actively discouraging bicycle travel while cleanup continued. Whether the canyon sees another round of slides depends on the same unstable terrain Lathrop described after the 2025 closure — a description the September 2026 sequence did nothing to contradict.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.