Deukmejian AG Opinion No. 81-1104-January 26, 1982
“MOBILE HOME PARK RECREATION BUILDING NOT PUBLIC FACILITY-Unless it is used by the general public, a recreation building in a mobile home park is not a “public accommodation or facility” within the meaning of Health & Saf. Code § 19955 so as to be required to be accessible to and usable by physically handicapped persons.”

You can find the entire opinion, a letter from U.S. Department of Justice regarding pools in mobilehome parks and ADA (1993), and letters from Assistant Attorney General in the Civil Rights Division in the right side panel on this page.