Little is known about this branch of the Dunder Mifflin Paper Company. In the episode Lecture Circuit Part 2 however, Michael mentions this branch when he and Pam skip the Rochester branch to go up to Nashua, New Hampshire, where Michael tries to reunite with Holly Flax.
The branch has presumably closed, since the (fictional) Sabre website does not include it in the list of Dunder Mifflin locations.http://www.sabre-corp.com/news-012010.shtml however it failed to list several branches that are proven to still remain open so it is possible this was just an unlisted branch.
In the episode, Survivor Man, Toby mentions that a man named Mark Chisholm attended Ryan's wilderness retreat, indicating that Chisholm is a regional manager. It is possible that he is the regional manager of the Rochester branch, though he could be the regional manager for Yonkers, Nashua, Akron, or Camden.