Coos County, New Hampshire’s largest, was created from Grafton County, one of the five original counties in the state. Comprising the entire area north of Grafton and Carroll counties, Coos was formed by a legislative enactment in 1803. In c. 1805 the southern boundary was modified by the addition of Nash and Sawyer’s Location and the deletion of the town of Chatham, later incorporated into Carroll County. Coos County was further reduced in size in 1853 when Bartlett, Jackson (Adams), and Hart’s Location were annexed to Carroll. Today forty-three towns, grant areas, and purchase and location districts comprise Coos County. To the west Coos is bounded by the Connecticut River, on the northwest and north by the Connecticut Lakes region and Canada, and on the east by the state of Maine.

Coos County is a sparsely settled rural area of over one million acres, much of which is hilly or mountainous terrain. Large portions of the White Mountain National Forest are situated in the southern sector. Traditionally, the economic life of the county has centered on farming and lumbering, with some activity in small industry and railroading. Paper manufacturing has been particularly prominent in Berlin, Groveton, and Whitefield. In recent years, the people of Coos have depended increasingly on income from recreation and tourism, especially in the White Mountain towns where the large resort hotels were established. Simultaneously, agriculture has declined and industry has failed to keep pace with other New Hampshire counties. As a consequence, the level of income is low and economic prospects for the future remain uncertain.

The architectural history of Coos County is very similar to that of Carroll County. Possessing comparable economic histories, topographies, and populations, the two counties have few buildings of pretentious character. Many, however, are of considerable regional interest and rank with the best New Hampshire examples of their respective styles, buildings types, and eras. Such a generalization holds particularly true for the town of Lancaster, which has a small but impressive collection of houses, churches, and public buildings dating from the period 1780 to 1890. Of the various building types present in the county, though, the most important is the large resort hotel, only a few examples of which remain today. The Mount Washington, Balsams, and Mountain View Grand hotels, all active business enterprises, are among the finest examples of grand hotel architecture surviving in the United States.