Colorado I-70 drivers are reminded that during the summer months, the highway through Glenwood Canyon may be closed on a moment’s notice due to flash-flood and mud/rockslide threats.

When the highway closes, drivers will be detoured on a 220-mile, four-hour alternate route via Meeker, Craig and Steamboat Springs, according to the Colorado Department of Transportation.

A flash flood watch was issued for the Grizzly Creek burn scar on the north rim of the canyon Aug. 1, but the highway remained open, according to CDOT.

Motorists planning to travel on I-70, visit rest areas or use the recreation path in Glenwood Canyon should pay close attention to weather forecasts. If there is rain in the forecast, it is possible there will be a safety closure of I-70, rest areas and recreation path, according to the CDOT advisory.

During a flash flood watch, CDOT officials said personnel and equipment will be on standby in preparation for a closure. Employees are stationed at closure points at exit 116 (Glenwood Springs) and exit 133 (Dotsero). Crews will also be on standby at exit 87 (West Rifle).

Evacuating travelers from the rest areas and recreation path requires significant time, so closing those locations ahead of time is necessary to allow a swift and safe evacuation of I-70 in Glenwood Canyon if a closure is needed, said CDOT.

Travelers can view closures for the Glenwood Canyon rest areas and recreation path on COtrip.org. Rest area and trail users can also check the status of the rest areas and riverside recreation path by calling CDOT’s Region 3 customer service information line at 970-243-2368, 8 a.m.-4:30 p.m.

Hikers with questions about the Hanging Lake Trail reservations should reach out to the vendor at 970-384-6309 or [email protected]. CDOT does not handle hiking reservations or have real-time information about reservations or parking.

Mudslides in July 2021 prompted an extended safety closure for I-70 for approximately two weeks as heavy rains washed mud and rocks onto the highway. CDOT has conducted extensive rockfall and debris flows prevention work in Glenwood Canyon since then.

Commercial river guide services, including rafting companies, continue to have access to the Grizzly Creek and Shoshone Power Plant exits during rest area and recreation path closures, unless a flash flood warning is issued and I-70 is closed. CDOT and partner agencies continue to coordinate with river outfitters. Commercial river trips are limited in number and closely tracked, and companies can be notified immediately if an evacuation is necessary. Companies with access during rest area and recreation path closures have committed to evacuating their customers if there is a Flash Flood Warning, or mudslides, and have liability insurance in place.

The new free COtrip Planner mobile app was designed to meet the growing trend of information on mobile and tablet devices for the traveling public. The COtrip Planner app provides statewide, real-time traffic information, and works on mobile devices that operate on the iOS and Android platforms. Visit the Google Play Store (Android devices) or the Apple Store (iOS devices) to download.

Those using Glenwood Canyon should also be aware of improvements to cellphone coverage in the canyon. AT&T installed a specialized cellphone system in the canyon that provides full coverage throughout the 17-mile canyon. The system went live in September 2021.

It’s dedicated primarily to emergency services, and special SIM cards issued to authorized users can access the AT&T FirstNet® nationwide communication system that leverages AT&Ts existing cellphone network, giving emergency responders priority over all cellphone calls except 911 emergency calls.

Under normal circumstances, the system operates as an ordinary cellphone system for AT&T customers traveling through the canyon. At the same time, anyone dialing 911 — even if they have a cellphone with a SIM card but no service plan — can reach emergency dispatchers without charge.