A mudslide and flash flooding forced the closure of Interstate 70 in western Colorado between New Castle and Silt [1, 2].

The closure disrupts a primary transportation artery in Garfield County, halting the flow of commercial and passenger traffic in both directions [2].

Heavy rain and flash flooding triggered the slide, which deposited mud and debris directly onto the roadway [1, 3]. The Colorado Department of Transportation (CDOT) said the closure occurred around 7 p.m. [1]. While Colorado Public Radio reported the event took place Tuesday, July 21, 2026 [1], Denver 7 reported the closure began Monday evening, July 20, 2026 [2].

Both directions of the interstate were shut down to ensure traveler safety [2]. A Garfield County emergency manager said, "The flash flood has caused significant damage to the roadway, forcing both directions of I‑70 to be closed" [2].

CDOT crews are on site to remove the accumulated debris. A spokesperson for the department said, "Crews are on site working to remove the mud and debris and will reopen the highway as soon as it is safe" [1].

Local authorities have urged the public to stay clear of the affected area. The Garfield County Sheriff’s Office said, "Residents are advised to avoid the area until conditions improve" [4].

In addition to the interstate closure, flash flooding has impacted other local infrastructure, including the closure of roads in Peach Valley [4]. Efforts to clear the highway continue as crews assess the full extent of the roadway damage [1, 4].

“"The flash flood has caused significant damage to the roadway, forcing both directions of I‑70 to be closed."”

The closure of I-70 highlights the vulnerability of Colorado's mountain corridors to extreme weather events. Because this stretch of highway is a critical link for interstate commerce and tourism, prolonged closures can lead to significant economic delays and force traffic onto smaller, less-equipped local roads that may also be compromised by flooding.