Lamoille County was established in 1836. It is bounded north by Franklin and Orleans Counties, east by Orleans and Caledonia Counties, south by Washington County, and west by Chittenden and a part of Franklin counties. This county lies on the Green Mountain range, and is the source of many streams. The River Lamoille passes nearly through its centre, and with its tributaries, gives the county a great hydraulic power. Hyde Park is the shire town.

(Gazetteer of Vermont by John Hayward, 1849, p. 79)