This dataset includes soil moisture data for the Bear Brook Watershed in Maine (BBWM). The BBWM consists of two watersheds, the reference East Bear (EB), receiving ambient deposition, and the treated West Bear (WB), which received experimental elevated N+S deposition for 27 years. Soil moisture sensors were installed at the site in 2003. Readings were taken every three hours -- three hourly readings and calculated daily averages are reported here.