At the entrance to the Pamunkey reservation is a sign announcing the tribe, which is the oldest documented tribe in Virginia. To the right is a small log cabin that is a re-creation of a trading post that was built on the reservation. (Timothy C. Wright/For The Washington Post)

The Pamunkey Indians, who claim Pocahontas as an ancestor and in July became the first state tribe to receive federal recognition, are facing a last-minute challenge by a California-based group that previously allied with casino giant MGM Resorts to try to block their bid.

Stand Up for California, a one-person nonprofit organization run by Cheryl Schmit, filed a request for reconsideration to the Interior Board of Indian Appeals on Tuesday, the last day of a 90-day window to appeal the Bureau of Indian Affairs’s decision to award the Pamunkey federal recognition. The move could delay or even derail the tribe’s goal of federal recognition, a status it has been seeking for more than three decades.

In a four-page letter, Schmit argued that the tribe did not meet many of the qualifications for federal status and that the very identity of the modern Pamunkey tribe is questionable. The letter said that current tribe members have not descended from Indian ancestors and that there was doubt as to whether the tribe operated as a functioning political entity, one of the requirements for recognition.

“I think I’ve submitted significant historical information that deserves reconsideration,” Schmitt said in an interview Thursday. “The ancestors they’ve identified do not appear to be members of the original tribe.”

On a cold wet, day last spring, Kevin Brown, then-chief of the Pamunkey tribe, pauses along the banks of the Pamunkey River where the tribe has its home. (Timothy C. Wright/For The Washington Post)

Schmit says she thinks the decision to give the 207-member Pamunkey tribe federal recognition did not strictly follow the guidelines. With 81 tribes in California seeking federal recognition, she worries that it sets a precedent that makes it too easy for tribes to meet the requirements.

Schmit’s assertions were vehemently rejected by the tribe.

“Stand Up for California’s request to the IBIA for reconsideration is unfounded, meritless, and unsupported by evidence,” Mark C. Tilden, the tribe’s attorney, said in a statement. “The Tribe’s sovereign strength, which traces back well before the arrival of the earliest colonists to Virginia, will see it through this frivolous attack as it has seen it through so many other thoughtless, mean-spirited attacks in the past.”

The Bureau of Indian Affairs on Thursday also dismissed the basis for Schmit’s complaints.

“We carefully considered the views offered by Stand Up for California, MGM and all the other comments that were submitted when we made the decision,” spokeswoman Nedra Darling said.

The appeal effectively puts an immediate hold on the tribe’s status, and it could be a long time before that is resolved.

Although the appeals board — an independent entity inside the Interior Department — has the authority to toss out this new request immediately, it is not known for speedy decision-making.

“Everything takes forever with the IBIA,” said a Washington lawyer deeply knowledgeable about Indian law, who spoke on the condition of anonymity because he occasionally has cases before the appeals board. “Even simple matters can take a very long time.”

There are 566 federally recognized tribes. The Pamunkey would be the 567th. An additional 356 tribes are seeking federal recognition and the money for housing, education and health care that comes with it.

Federal recognition is a fraught issue in many parts of the country because it is a first step for tribes interested in opening casinos or pursuing other gambling opportunities. In anti-casino Virginia, the Pamunkey’s effort has been closely watched — especially by MGM, which is set to open its $1.3 billion MGM National Harbor casino in Maryland’s Prince George’s County next year and is clearly concerned about possible competition in a bordering state.

MGM and Stand Up for California submitted a 39-page document opposing the Pamunkey’s recognition effort in July 2014. Other opponents of the tribe’s bid include Virginia gas station and convenience store owners, who worry that the tribe would be able to sell gas, alcohol and cigarettes without charging state taxes. Members of the Congressional Black Caucus opposed recognition because they say the tribe once forbade its members to marry African Americans.

The Pamunkey, who own a 1,200-acre reservation east of Richmond that was established in treaties with the English government in 1646 and 1677, have spent $2 million and 35 years seeking federal recognition.

The tribe’s history in Virginia is well documented. It was among the Native American tribes that greeted the first European settlers at Jamestown and provided the colonists with food and know-how as they sought to survive their first years on the continent. And each year during the week before Thanksgiving, in a much-publicized event, members of the Pamunkey and Mattaponi tribes present the governor of Virginia with two deer and a turkey.