The Feb. 27 letter from the chairman of the Colorado River Indian Tribes was pleading and tough. It asked President Obama to slow the federal government’s “frantic pursuit” of massive solar energy projects in the Mojave Desert because of possible damage to Native American cultural resources.

The Obama administration didn’t respond. But four days after Chairman Eldred Enas sent the letter, the Indians say they found an answer, delivered by spirits of the desert.

Howling winds uncovered a human tooth and a handful of burned bone fragments the size of quarters on a sand dune in the shadow of new solar power transmission towers. Indians say the discovery is evidence of a Native American cremation site not detected in Southern California Edison’s archaeological survey before the towers were built.

PHOTOS: Sacred ground

The Indians reburied the remains a few hundred feet away. But while digging the grave April 3, they hit more ancestral bones.

It was the last straw, the third discovery of artifacts at or in the vicinity of the $1-billion Genesis solar project 200 miles east of Los Angeles. All had been missed by archaeological surveys conducted in a rush to build.

“Mother Nature decided to show them what they missed in those surveys and said, ‘Stop,’” said Sylvia “Cindy” Homer, vice chairwoman of the Colorado tribes.

Now the tribes, joined by others in the desert, are not merely asking the Obama administration to go slow because of potential harm. They are demanding it. Backed by the legally powerful Native American Graves Protection and Repatriation Act, the Indians say Genesis and the transmission line corridor are proof of damage to sacred lands. They are readying court challenges that could alter solar and wind energy projects across the desert.

“We’re at a flash point over a general unwillingness to listen to and respect the tribal perspective and advice,” said David Singleton, a program analyst with the California Native American Heritage Commission. “These are important public policy questions involving gigantic power plants sprouting up in rural areas that had gone undisturbed for thousands of years.”

Genesis is one of 27 solar plants in the West that the U.S. Bureau of Land Management has identified as a priority, giving them a faster track to state and federal approval. Interior Secretary Ken Salazar has said the government is “on steroids” in its support for renewable energy.

But unless the developers and federal and state governments yield to the Native American concerns, they are headed for a showdown of complicated and competing values. It would come down to a single question: Does the cultural importance of long-buried Native American remains outweigh the need to rapidly build solar and wind energy projects to meet the enormous threat of global climate change?

In stark terms, should a project like Genesis be scuttled by what an executive for its owner called “a diffuse scatter of artifacts?”

The colliding interests are not new. They have been present for decades along the California coast, where most Native American village sites were destroyed by urbanization, said Jon Erlandson, director of the University of Oregon Museum of Cultural and Natural History and an archaeologist deeply knowledgeable about development in California Indian country.

“The relatively undeveloped deserts are next in line,” Erlandson said. “But out there, fast-track processes that do not involve a lot of thorough research before building something are setting the stage for future conflicts and potential disasters.”

Given the strength of the federal law protecting cultural artifacts, developers find that often it is less expensive “to slow down, consult with tribes and place projects in areas where they do the least amount of damage possible,” he said.

Although a handful of solar projects are under construction in the desert, Genesis has emerged as a case study for Native Americans. As a federally recognized tribal group with sovereignty over a 264,000-acre reservation, the Colorado tribes were offended that the BLM approved Genesis without holding “nation-to-nation” consultations with them.

Before construction began, archaeologists had warned that the site near Ford Dry Lake was rich with Native American history. Florida-based NextEra Energy Resources redesigned the project to avoid land most likely to hold artifacts, then followed a streamlined method, approved by state regulators, for surveying the new site for remains.

The survey found nothing to alter the project. But during construction last November, workers uncovered a pair of grinding stones and what appeared to be a layer of charcoal. The Colorado tribes say they are evidence of a sacred cremation site. Genesis claims they are insignificant artifacts. But work has been halted on more than 125 acres since their discovery.

The human remains found months later were some seven miles from Genesis, near new transmission towers erected to carry power from the project.

The tribes now want large areas surrounding the cremation sites deemed off-limits, even if that means redesigning Genesis and rerouting Southern California Edison’s transmission line corridor.

NextEra warns that yielding to the tribes’ demands could result in costly delays that jeopardize completion of the 250-megawatt plant, which is being built on BLM land with the help of an $825-million loan guaranteed by federal taxpayers.

Michael O’Sullivan, NextEra’s senior vice president of development, acknowledged in a recent letter to the BLM that the economic damage could be “so severe that, had they been known at the time the investment was approved, Genesis would not have moved forward with the project.”

California Public Utilities Commission spokeswoman Terrie Prosper said the human remains found recently were outside the boundary of the transmission line corridor and “no rerouting is necessary.”

But Linda Otero, a leader of the Fort Mojave Indian Tribe, which is working with the Colorado tribes, said that even though the remains were outside of the boundary, they are part of “a living spiritual world.” The utility has “disrupted the peace of our ancestors and our relationship with the land. There is no mitigation for such a loss.”

Native Americans insist they are not against renewable energy. The problem is that some solar projects were approved for lands that are an essential part of Indian religion, culture and history — without consultation with affected tribes.

The Colorado tribes and others in the desert are now joining to pressure developers and mount legal challenges. In Imperial County, for example, the Viejas Band of Kumeyaay Indians touts the support of the Cocopah, Quechan and Colorado tribes in its effort to derail Pattern Energy’s proposed Ocotillo Wind project, which would scatter across 12,500 acres of BLM land up to 112 turbines, each 450 feet tall.

“The problems inherent in this fast-track process are exacerbated by the sheer number of projects proposed,” Colorado tribes chairman Enas pointed out in his letter to Obama. “Our current count places over 40 proposed projects within a 50-mile radius of the Colorado River Indian Tribes Reservation.

“For projects that have been proposed but not yet approved, we ask that our input be sought out early and often, and that BLM be willing and able to turn down ill-sited projects,” Enas wrote.

Native American objections threaten to undermine the BLM’s efforts to create a plan to develop renewable energy across six Southwestern states. The agency is trying to unify local, state and federal land use rules into a uniform plan that developers can rely on throughout the region.

The plan has gotten off to a rocky start in Indian country, with many tribes not cooperating. BLM Deputy State Director Thomas Pogacnik acknowledged in an interview that Native Americans had good reason to be angry about his agency’s fast-track process, given that it relied almost entirely on information provided by developers to determine where to place the first “high-priority” wind and solar projects on public land.

Pogacnik promised that future projects will include more input from tribes. “We learned a lot from that first go-round of projects that there is a better way of doing things,” he said.

louis.sahagun@latimes.com

This is one in a series of occasional articles chronicling the wide-ranging effects on the West of the emerging solar-energy industry.