Note the letterhead: the Blue Mountain Forest Association is the formal name given to the exclusive 24,000 acre hunting preserve better known as Corbin Park, bordering the towns of Cornish, Croyden, Grantham, and Plainfield, New Hampshire. The preserve, established in 1888 by Long Island Railroad magnate Austin Corbin II, who was a native of Newport, New Hampshire, was stocked with many game animals, including wild boar, bison, and elk. Membership in the Association is said to be kept to more than a few dozen people at a time; it is still one of the most secretive hunting preserves in the country.
The letter writer is William Chandler, at the time the US Senator from New Hampshire. He mentions that he had been to see “Sen. [Justin] Morrill [of Vermont] at Strafford on Sunday & had a fine visit; & [Thomas C.] Platt [US Senator from New York] and [Redfield] Proctor [also a US Senator from Vermont] are now here.