@otto : For awhile someone had put signs up in English and Spanish re: No Dumping and fine - not sure if that's what worked, or if it was just the cleanup that followed (not sure if that was a local effort or if the county helped) that broke the pattern. Definitely much improved and I hope it stays that way! Unfortunately that hasn't stopped people from continuing to use it as a dog dumping ground.
Looking at Google Maps, it was part of Yarmouth and then the little stretch of Gloucester connecting that to Willaby that were notably bad last night. That Gloucester bit appears to be where all the previous Willaby trash dumpers are now concentrating. No wonder the creeks are so full of junk.
To get out of there, I was given good advice to follow Willaby west to the end, then up Shire a bit to Cambridge for real roads. That worked much better. On my way in I'd just been eyeballing the map to find the closest connections; glad I didn't have to do the reverse of that in the dark. I hate having to detour in that area at night; the connectivity isn't good enough for the phone maps to work well, the navigation can't handle detours or road names, and there's nowhere to just pull over to figure things out.