Founded in 1977, Friends of Grant Ranch Park is the volunteer association at Joseph D. Grant County Park. For 41 years, Friends of Grant Ranch Park has provided interpretive programs for the public of Santa Clara County and assisted park staff in a wide variety of other activities.

Organized in 1982 as the astronomical division of Friends of Grant Ranch Park, the Halls Valley Astronomical Group has been providing the public of Santa Clara County with monthly astronomical observing programs for 36 years. 

Halls Valley Astronomical Group starparties, which are scheduled every month throughout the year, make astronomical telescopes and interpretation available to the public under the dark skies of Halls Valley. 

Click on the image below to see more detailed information on the Weather and Viewing Conditions in Halls Valley