Wildfire burns near Las Vegas

Smoke from the Carpenter 1 fire in the Spring Mountains range partially obscures the setting sun behind hotel-casinos on the Las Vegas Strip July 9, 2013.

Nearly 20,000 acres have burned since lightning sparked the blaze in Carpenter Canyon, Nev., July 1.

More than 800 firefighters were battling the wildfire, which crested the peak of Mount Charleston July 11.

Read more: Mountain fire near Vegas burns six ranch structures

Smoke billows from the Carpenter 1 fire in Nevada's Spring Mountains National Recreation Area July 5, 2013.

Smoke and flames from the Carpenter 1 fire are seen along a ridgeline in Nevada's Spring Mountains National Recreation Area July 6, 2013.

Visitors at Red Rocks National Recreation Area look out at the Spring Mountains with smoke billowing beyond from a wildfire on Mount Charleston July 10, 2013.

Smoke from the Carpenter 1 fire in the Spring Mountains range is illuminated by the setting sun as it billows behind the Stratosphere Casino Hotel in Las Vegas July 8, 2013.

Public information officer James Stone talks on a phone in front of a briefing map for the Carpenter 1 fire at the incident command post at Centennial High School in Las Vegas July 10, 2013.

This image provided by the U.S. Forest Service shows the Carpenter 1 fire near Las Vegas July 10, 2013. The massive mountain wildfire that cast a smoky pall over Las Vegas destroyed six structures at a desert ranch and left two people in the firefighting force with minor injuries, officials said.

A family visiting the Red Rock Canyon National Conservation Area takes photos as smoke from the Carpenter 1 fire rises over Mount Charleston near Las Vegas July 9, 2013.

Joshua trees are silhouetted against a sky turned orange from smoke from the Carpenter 1 fire in the Spring Mountains range and other regional fires along Wheeler Pass in Pahrump, Nev., July 5, 2013.

Smoke from the Carpenter 1 fire in the Spring Mountains range is illuminated by the setting sun as it billows behind hotel-casinos on the Las Vegas Strip July 9, 2013.

With smoke billowing from a wildfire on Mount Charleston above the Spring Mountains, wild burros graze in a field at Spring Mountain Ranch State Park near Las Vegas July 10, 2013.