Lake Hennessey

Lake Hennessey is a reservoir in the Vaca Mountains, east of St. Helena and the Napa Valley. The reservoir is formed by Conn Creek Dam, built-in 1948 across Conn Creek. The lake was named after Edwin R. Hennessey. Hennessey was a local civic leader who played a role in the development of the Conn Valley reservoir.  You can enjoy hiking, fishing, and boating at Lake Hennessey.

The general public is permitted to enjoy the sports of boating and fishing at Lake Hennessey.

Please note that bodily contact with water is not permitted:

  • No swimming
  • No paddleboards
Lake Hennessey

Sage Canyon Road, St. Helena, CA 94574