Tests reveal fossils are at least 43,500 years old

The first radiocarbon tests of Ziegler Reservoir reveal some fossils found there are at least 43,500 years old.

Scientists tested samples from a piece of wood that was located beside an American mastodon in the lowest layer of the dig site and determined they were radiocarbon dead. That suggests fossils found in the silt layers at the bottom of the reservoir have been there 43,500 years, or exponentially longer.

Denver Museum of Nature & Science experts believe the fossils found in the reservoir above Snowmass Village are quite possibly from two different time periods, but more study is required. So far, multiple Ice Age mastodons, mammoths, bison, deer, a Jefferson's sloth, small reptile, small mouse-like mammal, snails and insects have been unearthed in Snowmass. There also is evidence of beavers.

The bones of a young Columbian female mammoth found Oct. 14 by a Gould Construction worker expanding the reservoir were initially estimated to are currently estimated at between 12,000 and 16,000 years old. Mammoths went extinct thousands of years ago but date back a few million years.

Ice age bison like the ones unearthed in Snowmass are usually found in American West sediments that are 30,000 to 50,000 years old. The U.S. Geological Survey Additional is conducting additional testing and analysis that should tell scientists more about the age of the sediment layers in the fossil site.

A new bone bed also exposed this week after crews removed a seven-foot American mastodon tusk from the earth. The bone bed includes fossils from an American mastodon, an Ice Age bison, an Ice Age deer and a well-preserved sloth tooth, which officials called a “real find” in the excavation.

All of the bones on the site will be washed in museum's conservation lab where scientists will closely inspect the fossils to determine how the animals died, and what happened to them after they passed.

The dig site is at about 8,870 feet — the highest elevation mastodons and giant grounds sloths have been found in Colorado. Remains of the Jefferson's sloth are the first ever recorded in Colorado. Moreover, there are no other known sites in the state that contain both mammoth and mastodon fossils.

A museum photographer is documenting the removal of the Columbian mammoth fossil discovered on Oct. 14. A temporary tent is sheltering the bones while the photographer shoots away so that a three-dimensional visualization of the original position of the fossils can be created on a computer.

Just beyond the dig site, the runs on Snowmass Ski Area are accruing more man-made and natural snow. It serves as a reminder that there aren't many days left this year for the Ice Age ecosystem excavation. With each day, the frozen ground is becoming harder to penetrate. Work may wind down in a few days.

River Name / Location	Stream flow, ft3/s	Gage height ft
Gore Creek
At Upper Station, Near I-70 Twin Bridges	n/a	4 ft
Booth Creek	n/a	4 ft
Abv Red Sandstone Creek At Vail	190	6 ft
At Mouth Near Minturn	223	7 ft
Beaver Creek
At Avon	21	2 ft
Lake Creek
Near Edwards	79	1 ft
Cross Creek
Near Minturn	100	4 ft
Homestake Creek
At Gold Park	127	5 ft
Eagle River
East Fork Eagle River Near Climax	n/a	2 ft
At Red Cliff	30	3 ft
Near Minturn	234	4 ft
Wastewater Treatment Plant At Avon	671	5 ft
Below Gypsum	826	5 ft
Colorado River
Near Kremmling	404	4 ft
Near Dotsero	1,630	3 ft
Below Glenwood Springs	3,140	5 ft
Near Cameo	3,740	6 ft
Below Grand Valley Div Nr Palisade	2,080	5 ft
Near Colorado-utah State Line	4,120	4 ft
Near Cisco, Ut	4,060	3 ft
At Lees Ferry, Az	12,100	9 ft
Near Grand Canyon, Az	12,200	9 ft
Yuma Main Canal Ww At Yuma, Az	987	10 ft
Roaring Fork River
Abv Lost Man Cr Near Aspen	n/a	n/a ft
Ab Difficult C Nr Aspen	53	1 ft
Near Aspen	78	1 ft
Near Emma	476	6 ft
At Glenwood Springs	1,160	3 ft
Hunter Creek
Near Aspen	56	2 ft
At Aspen	47	4 ft
Frying Pan River
Near Ruedi	113	2 ft
Crystal River
Abv Avalanche Crk, Near Redstone	540	2 ft
Arkansas River
Ef Arkansas R At Us Highway 24, Nr Leadville	47	3 ft
Near Leadville	86	5 ft
Below Empire Gulch Near Malta	156	3 ft
Below Granite	453	4 ft
Near Nathrop	451	4 ft
At Parkdale	464	3 ft