Arlene C. Luther, 59, a longtime leader in the Navajo Nation Environmental Protection Agency, died Sunday at University of New Mexico Hospital in Albuquerque after a brief illness.

Navajo Nation President Joe Shirley Jr. called Ms. Luther's death the loss of the nation's greatest environmental champion and a sad day for Native people everywhere.

"Arlene was among the first generation of environmental professionals, and she set an incredibly high standard for the people who will follow her," Shirley said. "She helped create and build the Navajo Nation's Environmental Protection Agency into the pre-eminent Native American environmental department in the country."

Ms. Luther headed the agency's Waste Regulatory Compliance Department and had worked at the agency for 27 years. She helped to establish the regulatory

capabilities of the Navajo Nation EPA and was key in convincing the federal EPA it was responsible for the cleanup of the Church Rock Mine on Navajo Nation land.

A funeral was to be held today in Gallup, N.M.