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Media Alert: Flights Above Custer and Fremont Counties, Colorado, to Map Geology

USGS Low-level Helicopter Surveys Begin Early June


Editor: In the public interest and in accordance with Federal Aviation Administration regulations, the USGS is announcing this low-level airborne project. Your assistance in informing the local communities is appreciated.


A low-flying helicopter will soon be visible to residents of Custer and Fremont counties, Colorado, beginning on or around June 4 and lasting potentially through August 31, 2021. The helicopter will be equipped with an elongate “stinger” mounted to the underside of the cabin extending forward of the helicopter.


The low-level flights are coordinated by U.S. Geological Survey scientists to image geology at the surface and below ground. The effort is part of the USGS Earth MRI project in collaboration with the Colorado Geological Survey to assist in better understanding the geology and natural resources in the area.

SGL Stinger Helicopter
Sander Geophysics Limited helicopter with a “stinger” that senses the magnetic field. Photo courtesy SGL.


Instruments on the airplane will measure variations in the Earth’s magnetic field and natural low-level radiation created by different rock types near and up to several miles beneath the surface. This information will help researchers develop geologic maps of the area that will be used to better understand the geology and mineral resources in the region. The scientific instruments on the airplane are completely passive with no emissions that pose a risk to humans, animals or plant life.

This survey will be flown at an altitude of 300 to 1,000 feet above ground by contractor Sander Geophysics Limited. Experienced pilots who are specially trained and approved for low-level flying will operate the aircraft. All flights will occur during daylight hours and are coordinated with the FAA to ensure accordance with U.S. law. The flights will be based out of Fremont County airport near Cañon City, covering parts of the Wet Mountains and Wet Mountain Valley in Fremont and Custer Counties, including the town of Westcliffe.


Map of Low-level Helicopter Survey in Colorado
The helicopter survey will take place within the red polygon on the map, located just west of Cañon City, Colorado. It will cover parts of the Wet Mountains and Wet Mountain Valley in Fremont and Custer Counties, including the town of Westcliffe, in south-central Colorado.

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