Was in the area last week for a few days and checked out the remaining trackage as best I could from adjacent roads.
Caribou branch has three active shippers.....the propane terminal (one spot, one car being unloaded), the scrap yard at the north end of the yard (three SSEX scrap hoppers spotted for loading) and the MPG grain terminal in Presque Isle (two spot, two 100 ton hoppers being loaded). The track on this side is in incredibly bad shape, with most ties being nothing more than splinters. There were Maine Northern track machines in the Preque Isle yard, and stack of new ties. Other than that the yard was vacant. I saw no evidence of track work, but obviously some is under way, or about to be. A large tree has fallen across the tracks just north of the Caribou yard and obviously nothing has gone up that way in many years. Tracks have been removed in spots in Limestone proper (including the 1A crossing), but are still in place north and south of there, although heavily overgrown and not easily visible.
The Fort Fairfield side is much more active and the track appears to be in much better condition. As earlier stated, there are two good customers, right next to each other, in Easton. Huber makes wooden veneer and flooring and it appears it ships outbound loads in boxcars. A few spotted and some waiting for spot. McCain produces and packages frozen potato products (fries, tater tots, hash browns, etc) and takes tank cars of vegetable oil in their production. The cold storage warehouse, where the finished product is stored prior to shipment has no rail access and hence their entire product appears to go out by truck. (Many Prime trucking refrigerated trailers on site.) The new fertilizer plant seems active, although there were no cars spotted there last week. The trackage beyond into Fort Fairfield appears to be used, but I couldn't find an active shipper. In Fort Fairfield itself there are no shippers and the track is heavily rusted.
There were no cars in the Squa Pan yard (other than mow) and no locomotives, although I was only there one time. Obviously Easton is the source of most of the traffic up here and lacking a new source of traffic the Caribou side is probably not on steady ground.