So I decided to try to map out the approximate locations of the dots on this map. My method was to hold the cursor over Google maps where it looked like the pin would be, and zoom in until I identified something. The map in the show was (obviously) not 100% accurate so this is just a best guess scenario.

From East to West:

Florida: Disney World.
Alabama: the Taladega Forest or possibly Lake Martin
Pennsylvania: in Johnstown/Somerset area
New York: Between several towns (Cohocton, Wheeler, and Prattsburg)
Indiana: Fort Wayne [edit: says The Beast of Busco in nearby Churubusco is more likely], or Churubusco
Illinois: the city of Normal, (but I bet they were going for Springfield)
Wisconsin: Lake Wisconsin, and somewhere near Wausau or Merrill
Minnesota: Brainerd [edit: makes a good case for the location being Milford Mine, which had a flood in 1924 that killed almost everyone in the mine, and is considered haunted], Milford Mine
Nebraska: Clearwater
Wyoming: Hole-in-the-Wall Lake
Montana: Fort Peck, Geraldine, Helena, Great Falls
Utah: Salt Lake City, Argyle Ridge
Arizona: Between Dilkon and Indian Wells
Nevada: Elko, Rochester, Chukar Ridge
California: Lake Almanor, Rancho Tehama Reserve, Tulelake
Idaho: Atomic City, Gold Creek, Cottonwood, Burgdorf,  Fruitvale, a big empty spot between Weiser and Garden Valley, Stanley, Mountain Home Air Force Base
Washington: Lacrosse, Keller, Tonasket, Indian Dan State Wildlife Recreation Area, Wenatchee, Hatton, Mesa, Hanford [an ex-nuclear site!], Walla Walla, way too many sites near the Oregon border, Yakima, Morton, an area between Carson and Trout lake, Badger Gulch, Mt. Buckindy

I will add Oregon later, my wrists hurrrrt