Well this one an interesting one. When I first pulled into the parking area, I noticed some one heading out to the memorial with her dog. Apparently she couldn't read the signs so I just assumed that it must have been a guide dog. I also assumed that she was a muggle so left to get some gas and a snack and when I returned the coast was clear.
By the way the causeway happens to be very icy under the snow so use caution if you decide to grab this cache.
I confirmed some guesses and located the info for the rest of the puzzle coords and made my way gingerly (still slippery) to the final location for the quick find. Since there was no one else around I decided to take the cache back to the car to warm up my hands before signing the log. Bad idea as it turned out because I had just reached my car when another vehicle pulled into the lot, disembarked with his dog and headed straight for the final location. Then while I was waiting for the dog walker to clear the area, another vehicle pulled in to the area and parked near the final location and directly facing it. So I waited. The dog and walker finished their walk but there was still no way to safely rerun the cache to its hiding spot. The latest muggle was sitting in her and making no effort to move. I waited and waited and hoped that she would eventually get cold and move on. Well apparently she got cold because she started her car but still didn't move. I waited another 15 minutes and still no movement. Not sure what she was doing there but she probably thought the same thing about me. After waiting another 15 minutes with no sign of any movement I had to get back on the road. So I took the cache with me and returned to the area tonight on my way home. Believe it or not there was another muggle in the parking area. Fortunately that muggle moved on as soon as I arrived so I was able to return the cache to its proper place. I was somewhat relieved to see that there were no footprints in the snow other than mine so at least no other cacher was looking for the cache after I had spirited away with it.
TFTC and thanks for the adventure. I think this is the first time that I've had to leave with a cache because of muggle activity.