Before moving to Bellingham I was a member of the United States Postal Service. I loved the gig! So much walking, exploring, and what a way to meet you neighbors! I was always amazed at just how complex the whole system of carrying and moving letters was, and to this day I'm somewhat bamboozled by how we got our job done everyday. This puzzle is based on some of the very clever ways in which our mail is delivered to us. You'll need an online tool to help complete it, but I'm sure you'll figure it out... 
N:
417 Ridgeway Dr., Bellingham, WA 98225
1905 22nd St., Bellingham, WA 98225
1618 Donovan Ave., Bellingham, WA 98225
W:
206 Prospect St., Bellingham, Wa 98225
3404 Sitka Ct., Bellingham, WA 98226
120 Grand Ave., Bellingham, WA 98225
704 Willow Ct. S., Bellingham, WA 98225