The fire has been burning since a lighting strike July 1, charring an estimated 14,458 acres 35 miles northwest of Las Vegas, forcing the evacuation of more than 500 people and threatening hundreds of structures.
The declaration came following a request from Gov. Brian Sandoval for a Fire Management Assistance Grant.
Local residents Sunday expressed anger at a town hall meeting because of the lack of information on how the blaze was being handled, the Las Vegan Sun reported.
Evacuee Katie Tomashowski Corr, 24, told the meeting at Centennial High School she would hear horror stories about the fire, eventually debunked, whenever she spoke to police.
Several residents grew passionate in demanding details of the decision-making process in the first few days of the fire, the newspaper said, noting many asked how aircraft resources were deployed.
Clark County officials said the fire was 15 percent contained.
Rich Harvey, team incident commander, said over 700 people were fighting the fire.
"We know this is not a one-day event. It's going to be a grind. We know it. We're ready for the grind."
The Sun said a second meeting was scheduled for Monday evening at the high school.