Las Vegas Sun

March 24, 2018

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Researchers hoping to protect fossil sites

Scientists have discovered a nearly complete fossil record in the Las Vegas Valley, a record that dates back 190,000 years.

Researchers were combing 22,000 acres cupping the northern edge of Las Vegas on Bureau of Land Management land, including parcels ripe for an auction that would hand about 5,000 acres over to developers. In the process, they discovered hundreds of ancient animal bones and two living rare plants.

Fossil fragments of mammoths, horses and camels that roamed Southern Nevada 11,000 years ago and other signs of life that may have thrived as long as 190,000 years ago captured the attention of federal, state and local representatives who spent four hours viewing them Tuesday in sediments along a dry stream bed.

Archaeologists, biologists, botanists and other experts have teamed up to protect exposed fossil bones at 438 sites spread along a 10-mile-long swath running north of Las Vegas and North Las Vegas.

"It seems we have so little left in this valley worth preserving," said Eric Scott, curator of paleontology at the San Bernardino County Museum in Redlands, Calif., who is leading researchers piecing together the fossil record.

The possibility of not auctioning off some of the land came as an unpleasant surprise to area developers in November, when they learned that ancient bones and unique plants could stand in the way of their planned growth.

Floods and droughts have come and gone in the valley for eons. Every time it rains or the wind blows, erosion exposes new evidence for bone hunters. And each day in the field could bring scientists closer to finding evidence of ancient man, Scott said.

Unlike the La Brea Tarpits in Los Angeles, which contain only the bones of predators and prey going back 38,000 years, Southern Nevada's cache of ancient treasures could explain how animals and plants lived through multiple eras, Scott said.

The latest research estimates conclude that some of the fossils found in the valley may be 190,000 years old, based on the dating of calcium carbonate contained in seashells buried in valley sediments, Scott said.

So many bones are at the surface that looters have raided the fossil sites for 50 years, a fact that keeps researchers from revealing the exact location where the remains can be viewed until all the fragments have been recorded.

"It's not the size of the site, it's what's in it," Scott said. "Nowhere else in the Mojave Desert can you track the species like you can here."

Scientists also discovered a unique shrub, the Las Vegas buckwheat, along with Las Vegas bearpoppy plants, which grow in poor soil.

"This is the last great place in the valley for conservation," Rob Mrowka, planning manager for the Clark County Comprehensive Environmental Planning Division, said.

Some day, if the area is preserved, trails may link the Upper Las Vegas Wash in the northern valley with the main wash along its eastern edge, Mrowka said.

The Bureau of Land Management issued a draft environmental impact statement in November that grows with new information as scientists continue to discover interesting bits of history in the area.

For the next year, the bureau, with federal, state and local help, plans to develop a Conservation Transfer Area where research can continue on the fossil sites and the plants can be protected, said Jeff Steinmetz, BLM project manager.

"We know there are many, many resources out there," Steinmetz said during the tour.

A final decision on environmental issues in the area is expected to be released for a 30-day appeal period on Dec. 17.

"We expect lawsuits," after the release of the final environmental impact statement, Steinmetz said.

The public will have another say on conservation efforts from 5:30 p.m. to 8:30 p.m. on Jan. 10 at the Bureau of Land Management office, 4701 N. Torrey Pines Drive, east of Rancho Drive.

The city of North Las Vegas has withdrawn its bid for the sensitive lands scheduled for a proposed February auction by the Bureau of Land Management.

BLM Associate Field Manager Angie Lara said that 5,000 to 8,000 acres in the Upper Las Vegas Wash is of particular concern.

The area of concern includes Tule Springs, a 980-acre site where Columbian mammoths, camels, bisons and horses were found in the 1960s, BLM archaeologist Stan Rolf said.

Of the 438 new "significant" fossil sites discovered, 200 of them contain mammoth bones.

Rolf said that the proposed Conservation Transfer Area is considered one of the richest ancient geological sites west of the Mississippi River.

"It's one of the best sites in the Great Basin," Rolf said of recent discoveries that prompted him to urge protecting the entire area, rather than pockets of fossils.

In 1962 one of the largest archaeological digs in the world occurred in the area to determine if early man emerged from the fossils in the wash. Known as "The Big Dig," scientists invented Carbon-14 dating during the 9-month fossil hunt. Though the archaeologists did discover mammoth, horse, camel and bison bones, no human remains were unearthed.

That research helped put the Tule Springs site on the National Registry of Historic Places.

"It should be preserved for further research," amateur archaeologist, spelunker and fossil hunter Helen Mortenson of Las Vegas said.

Geoscience professor Steve Rowland of the University of Nevada, Las Vegas, agreed with Mortenson. He is helping students at nearby Shadow Ridge High School on Brent Lane learn about the fossil treasures.

"Students learn a sense of place by studying such unique areas," Rowland said.

The two rare, living plants occupy a habitat described as "badlands" on an old lake site known as the Las Vegas Formation, said Gayle Marrs-Smith, a BLM botanist.

"The Las Vegas buckwheat is one of the plants that thrives in such soil," Marrs-Smith said. Researcher James Reveal has proved through DNA tests that the Las Vegas buckwheat is unique.

The Las Vegas bearpoppy is listed on a multi-species habitat conservation plan drawn up in the 1990s after the Mojave Desert tortoise was listed as endangered.

The poppy is considered a sensitive species by the BLM and "critically endangered" by the state.

The bearpoppy cannot be grown from seed, but scientists are trying to nurture it in seed banks and are studying other methods to preserve it.

The Las Vegas buckwheat, however, is not covered by the county's conservation plan.

The buckwheat has been proposed as critically endangered by the state and it was not known to exist until the survey in the northern part of the valley was completed. There are three known populations of the plant and fewer than 8,000 of the shrubs exist, Marrs-Smith said.

No formal request has been received by the Nevada Division of Forestry to list the buckwheat, said Lisa Ortega, resource manager for the state division.

"If you can work with the community to protect it, you don't need to list it," Ortega said. "Protection is the key."

In addition to fossils and plants, water quality issues have drawn Clark County Regional Flood Control District and federal Environmental Protection Agency officials into the plan to protect the area.

Rain runoff from the area and how it affects water quality in the Las Vegas Wash is being studied as natural environments grow scarcer amid the continuing rapid development of Southern Nevada.

The Clean Water Act must be considered to ensure water quality for the entire valley, EPA environmental protection specialist Audrey Liu of San Francisco said.

The Regional Flood Control District is urging the Bureau of Land Management to keep the sensitive area natural to avoid water quality and flood control problems.

The Upper Las Vegas Wash offers natural flood control and provides some filtering to improve water quality downstream.

Officials said that if there is not enough of a buffer between the wash and development, lives and property could be threatened.

In the draft environmental impact statement, flood control was not considered, but it will be included in the final statement, Steinmetz said.