WINDOW ROCK - President Joe Shirley Jr., called the loss of the Navajo Nation's greatest environmental champion a sad day for Native people everywhere. Arlene C. Luther, 59, who was department manager for the Navajo Nation Environmental Protection Agency's Waste Regulatory Compliance Department and employed by the Navajo EPA for 27 years, passed away Sunday, Jan. 6, at University of New Mexico Hospital in Albuquerque after a brief illness.