The most recent lava flow in Colorado occurred in Eagle County. This was approximately 4,000 years ago ( think Stonehenge) as determined by radiocarbon dating of a tree found in the ash in 1962. Local historians weren’t available for documentation purposes, however, according to an article written by Allen Best in 1990 [Vail Trail Dec. 7, 1990], there would have been a native American local population to witness the event. If you drive by the Dotsero exit on I-70, look at the hillside above the trailer court. This is one side of the cone that produced the lava. According to the late Ogden Tweto of the U.S. Geological Survey, Colorado has a volcanic rock similar to that found in Hawaii, so the eruption probably produced a flow of lava through a vent rather than a wild explosion. Looking at the area south of the Interstate, the remnants of that flow are clearly visible. Ogden Tweto, by the way, revised the state geologic map during the late sixties, early seventies. It was published in 1979 and “has been acclaimed the best map of its kind to appear anywhere and sets a high standard for other states to follow.” – L. A. Warner, in his “Memorial of Ogden L. Tweto 1912-1983,” in American Mineralogist, v. 72, p. 1271-1272, 1987.
The volcano crater at Dotsero has not become a heritage tourism site nor has it even been deemed deserving of a roadside marker. It is on BLM property and access is on property owned by Mayne Block and Stone, which quarries the cinders (scoria) and compresses them into building blocks. Public access has been possible in order to travel several hundred feet up the valley floor to view the crater.
Comments