GRAND JUNCTION — The funnel-shaped twister that touched down on the crest of Mount Evans Saturday has been confirmed as a tornado — the second highest ever recorded by the National Weather Service in the United States.

“It’s not unprecedented to have tornadoes in the mountains. But they are rare,” said National Weather Service meteorologist David Barjenbruch.

Barjenbruch said at 11,900 feet the tornado was above treeline and did not do any damage. He said it did surprise many drivers on Mount Evans, some of whom were above the tornado and had the rare opportunity to look down into the funnel.

Josh Deere of Colorado Springs was driving with his family to the top of Mount Evans when he saw the funnel near Summit Lake. Deere, who grew up in the “tornado alley” of Oklahoma, said the twister made him “a bit antsy” so he decided to drive up the mountain to get away from it — a choice that took him within a few hundred yards of the tornado.

“As we drove past it, we were able to look back and had some spectacular views of it as it spun and then eventually broke up as it entered the mountain cove,” Deere wrote in an email description of the encounter.

Witnesses posted pictures on Facebook, and the weather service was able to use those pictures and accounts as well as documentation from an official weather spotter and from Google Earth to determine the funnel-shaped cloud was truly a tornado and to place the tornado’s touchdown point. Barjenbruch called it a “weak” twister.

He said tornadoes in the mountains generally are shorter-lived and weaker than tornadoes that form in more open terrain. But there have been strong, damaging tornadoes recorded.

The most violent mountain tornado occurred in Wyoming in 1987 and tore up a forest at 10,000 feet as it passed over the Continental Divide. Another violent twister occured in Utah in 1992. The only tornado to beat the Mount Evans twister in elevation occured in 2004 in Sequoia National Park in California at 12,000 feet.

Barjenbruch said it is hard to say if the numbers of mountain tornadoes are increasing because there is no good historical record for comparison. He said the twisters are more often reported and verified now because more people are in the mountains and are able to document the weather phenomenon with smart phones and cameras.

Nancy Lofholm: 970-256-1957, nlofholm@denverpost.com or twitter.com/nlofholm