Hi,
Maybe some of you have already read these articles, but if any of you have access to academic journals, these two are amazing articles loaded with pictures and explanations:
1) Griswold, E.N. 1939. Hunting boundaries with car and camera in the Northeastern United States. Geographical Review, 29(3): 353-382.
2) Ritter, G. and Hajdu, J.G. 1989. The east-west German boundary. Geographical Review, 79(3): 326-344.
The 1939 article is especially insightful. It shows many pictures of some of the earlier border markers in the NE USA and the US-Canada border.
Speaking of this, I found an old stone marker on the Rhode Island-Connecticut border under some poison ivy and other brush that was the original border marker from the colonial days. The C and R were just barely visible and I believe the year was 1679 or thereabouts. This too was barely visible. This was in 1996, so I hope they haven't thrown it away.
Dallen