In 1945, NH RSA 432 established New Hampshire's conservation districts to set local priorities and to deliver information and assistance to landowners and users. Over the next year, ten county conservation districts were established:
- October 10, 1945: Cheshire County
- January 24, 1946: Merrimack County, Sullivan County
- February 14, 1946: Belknap County
- March 8, 1946: Hillsborough County
- April 24, 1946: Coös County, Grafton County
- April 25, 1946: Carroll County, Strafford County
- April 26, 1946: Rockingham County