Window areas and magnetic deviation
Per Operation Trojan Horse by John Keel, window areas tend to be centered around locations with higher levels of magnetic deviation.
Every state in the United States has from two to ten “windows.” These are areas where UFOs appear repeatedly year after year. The objects will appear in these places and pursue courses throughout the 200-mile limitation. These window areas seem to form larger circles of activities. The great circle from Canada (not to be confused with the traditional geographic Great Circle) in the northwest through the Central States and back into northeast Canada is a major window. Hundreds of smaller windows lie inside that circle. Another major window is centered in the Gulf of Mexico and encompasses much of Mexico, Texas, and the Southwest.
Many windows center directly over areas of magnetic deviation such as Kearney, Nebraska; Wanaque, New Jersey; Ravenna, Ohio. In the 1950s, teams from the national Geological Survey Office quietly flew specially equipped planes over most of the United States and mapped all of the magnetic faults in the country. You can obtain a magnetic map of your locale from the Office of the Geological Survey, Washington, D.C. 20242. If you have been collecting UFO reports in your home state, you will probably find that many of those reports are concentrated in areas where magnetic faults or deviations exist.
See also: UFO electromagnetic [[ Electromagnetism, UFOs, and psychic abilities ]] Window areas and how to find magnetic faults near you