Update April 13, 11 AM -
The mud flow on Red Mountain has continued to flow and remains active. Red Mountain Road remains unpassable past the gate. Some of the smaller culverts on Red Mountain are experiencing blockages from debris build up. City crews continue to make efforts to clear the road, and blockages and are working to contain and direct the flow to drainage ditches.
Geotechnical experts are working with City staff to gather information about this flow and evaluate if there are other points of vulnerability. Early findings indicate that part of the mountainside very high up on Red Mountain sluffed off into the drainage, adding to the velocity and quantity of the water coming from the mountain. As snow continues to melt, additional mud flows are possible.
New photos and video will be made available later today.
Grandstaff Trail and the Jeanne Golay Trail (Red Mountain Trail) are closed. Hikers should avoid the area for the next few days until the mud dries out.
Wet trails are fragile. Do not try to avoid mud by going to the side of a trail. Doing so damages plants that keep trails in place and can cause trail damage. Hiking or riding on muddy trails causes damage to trails through erosion, especially if you are leaving deep footprints or tire tracks.
Additionally, during spring runoff, if you encounter a stream of water crossing a trail the safest option is to turn around rather than risk crossing. During peak runoff, mountain snowmelt can quickly turn gentle streams into uncrossable paths.
Update April 12, 8 PM -
City crews have made progress clearing the road and will continue to monitor the area overnight. Additional road repair will be required. Hikers should continue to avoid the area for the next few days until the mud dries out.
The next update will be shared tomorrow morning.
Correction - This is due to an active mud flow. This post previously misidentified the issue as a mudslide.
Red Mountain Trail (the road that is near the Red Mountain treatment plant) is closed at the gate, just west of W. 9th Street due to an active mud flow*. City crews are responding. There is no estimated time of reopening. More information will be shared as it becomes available.