During the fifties and sixties, several Aircraft Control and Warning (AC & W) "gap filler" sites were constructed along the borders of the United States and across many of the "lower 48" states and Canada. These sites filled in the low altitude gaps between the long-range radar stations.
Sites built before 1958 would have been part of a manual radar defense network. After 1958, new sites would have been part of the Semi-Automatic Ground Enviroment (SAGE) radar network and existing sites would have been upgraded. The last gap filler site in Maine was closed in 1968 and their phase-out continued across the country until approximately 1970.
The Bridgewater gap filler site sits atop Number 9 Mountain, west of Bridgewater, Maine. To reach it from Bangor, take I-95 north to Houlton and then take Route 1 north to Bridgewater. At the school, turn left on to Bootfoot Rd and head west to Number 9 Mountain. Drive around to the back side of the mountain and you'll come to a steep road with a yellow gate. This is the access road and it travels right up the side of the mountain. If you're having trouble, try to stick with the power lines. This is a good rule of thumb for finding any military site in a rural area. Military sites will have generators, but they will almost certainly have power and telephone running to them. Another great tool to have is a Maine Gazetteer from DeLorme. Throw your Garmin in the woods and rock out with the Gazetteer. It won't talk to you (unless you're on acid), but it will get you anywhere you want to go in rural Maine.
Much like the other images on this site, I've visited this radome a few times so the images may be chronologically out of order and, instead, placed in an order that loosely makes sense. All pictures were taken between the fall of 2008 and summer of 2009.
Thanks to my good friend, Jim, for taking some of these photos on our trip.
Thanks to Tom Page for helping me get the correct background information on this site.