Alta Loma is one of three formerly unincorporated areas that became part of the city of Rancho Cucamonga, California in 1977. Alta Loma is one of the more affluent areas in San Bernardino County. It is almost completely residential and, by city ordinance, no commercial business may exist above 19th Street, with the exception of several businesses already in place when the ordinance was enacted (notably at the intersection of Lemon Avenue and Haven Avenue). In addition, homes north of Banyan Street must have a minimum of 1/2 acre lots, with the exception of the development known as “Compass Rose Phase II”, directly west of Chaffey College (between Banyan Street and Wilson Avenue). Compass Rose Phase II was granted permission for smaller lots provided the development connected to city sewer systems instead of septic tanks. For some reason, all of the homes in Compass Rose are on septic tanks. The community of Alta Loma is located mostly in the northwest corner of Rancho Cucamonga. The exact definitions of the three communities (Cucamonga, Etiwanda, and Alta Loma) within the City of Rancho Cucamonga are debatable; however, residents typically consider Alta Loma to be above Baseline Street (Old Route 30), between the eastern edge of Upland and west of Day Creek, a boundary later moved to Day Creek Boulevard when the then-future road was plotted on Chamber of Commerce maps dating to about 1980. Most street signs in the Rancho Cucamonga area stretching from Carnelian Street to Milliken Avenue, and Baseline Road to the mountains, have an Alta Loma logo. Some residents of Rancho Cucamonga, especially those in the former Cucamonga area, have challenged the city council to get rid of the names “Alta Loma” and “Etiwanda,” accusing residents in those areas of keeping the names out of arrogance. The three communities incorporated after years of debate and at least one failed attempt on the ballot. Residents of Alta Loma and Etiwanda finally agreed to incorporation provided their identifying community names would be kept along with separate post offices and zip codes. In addition, businesses are permitted to use either Alta Loma or Rancho Cucamonga on letterheads, business permits, and other records.