Holbrook in Navajo County, Arizona — The American Mountains (Southwest)
But clean air is extremely sensitive. In pre-industrial times, visibility fluctuated naturally depending on conditions of weather, wind, dust, and smoke. Today, visibility also is affected by man-made pollutants that reduce contrast, wash out colors, and render distant landscape features indistinct or invisible.
Most of these pollutants are fine particles of sulfates, organic matter, soot, nitrates, and soil dust from industry, farming, motor vehicles, forest fires, and other sources.
As in many rural western areas, sulfates, organic matter, and soot contribute almost equally to decreased visibility. The park's air quality equipment measures and monitors the amount of these fine particles in the atmosphere.
Erected by Petrified National Forest Services.
Topics. This historical marker is listed in these topic lists: Natural Features • Notable Places.
Location. 35° 4.892′ N, 109° 48.098′ W. Marker is in Holbrook, Arizona, in Navajo County. Marker can be reached from Petrified Forest Road, on the left when traveling east. Touch for map. Marker is in this post office area: Holbrook AZ 86025, United States of America. Touch for directions.
Other nearby markers. At least 8 other markers are within 2 miles of this marker, measured as the crow flies. Painted Desert Inn (approx. ¾ mile away); Badlands (approx. 0.8 miles away); A Gap in the Geologic Record (approx. one mile away); Over the Edge (approx. one mile away); Early Explorers (approx. 1.1 miles away); The Painted Desert (approx. 1.3 miles away); A Painted Park (approx. 1.4 miles away); Painted Desert Community Complex Historic District (approx. 1½ miles away). Touch for a list and map of all markers in Holbrook.
Credits. This page was last revised on June 16, 2016. It was originally submitted on September 29, 2013, by Denise Boose of Tehachapi, California. This page has been viewed 529 times since then and 37 times this year. Photos: 1, 2, 3, 4, 5, 6. submitted on September 29, 2013, by Denise Boose of Tehachapi, California. • Syd Whittle was the editor who published this page.