Rock Valley is a populated place LOCATED WITHIN the City of Holyoke. In turn, the City of Holyoke is located within Hampden County.
Rock Valley is located at latitude 42.194 and longitude -72.676.
Since Rock Valley is located within the City of Holyoke, all of the census and demographic data for residents of Rock Valley are included as part of the information reported for City of Holyoke in the "Profile" tab above.