Image copyright 2007.
Thursday morning, Sept 27, I noticed the unusual cloud rising from the long ridge running northly to southerly east of Coram, Montana. The ridge is likely to be Desert Mountain in the Flathead National Forest. At first, I thought perhaps a fire had started near the top edge of the long ridge, but after watching for several minutes, the cloud indeed appeared indeed to be a cloud. The camera was hand-held, using my Fz50 set with IS-2. Would that I had begun photographing when first I saw the image, but I didn't. So at least 15 minutes were not photographed. All the while, the Sun was rising behind the mountains, thus changing the light illuminating the cloud. I've lived in the Rockies for 29 years and have never seen a cloud formation like this one, rising high above one of the higher ridges in a mountainous locale that includes Glacier National Park.
The same curve of the ridge can be seen in a small section of daylight photo taken appx 1/3 mile north of where the funnel cloud was photographed, but at appx the same distance away from the north-south ridge of Desert Mountain.
http://www.pbase.com/aspergerian/image/86349490
On June 14, 2010, a funnel cloud near Leadville, Colorado, was reported by 9News and summarized in The Denver Post
http://www.denverpost.com/news/ci_15291559?source=bb
.