Alta Loma (and much of the rest of Cucamonga) was previously home to old citrus groves and grape vineyards. The purpose many homes above Banyan Street, in suitable, have orange and lemon trees on their property may be associated to this; many horse trails are lined with eucalyptus trees, which are former windbreaks for the groves. Even amidst the office buildings and shopping malls that have been built in recent decades, the occasional patch of greenfield has a few rows of grapevines.
Rancho Cucamonga, Alta Loma and Etiwanda were most affected by the October 2003 Grand Prix fire, which combined with the Old Fire. The Grand Prix fire, which began October 21, 2003, ripped across the mountains just above and, in some places, down into Alta Loma and Etiwanda for six days. Overgrown brush fueled fire, which ran across the mountain tops and higher foothills to eventually fly into the canyons that are surrounded by homes. It destroyed 13 homes (including 2 mobile homes) and five outbuildings, and damaged 9 others in Alta Loma.
The Alta Loma area experiences high winds known in the Inland Empire and the rest of Southern California as the “Santa Ana winds.” Heavy rain storms in the past created the need for 12–18-foot-deep (3.7–5.5 m) concrete flood control channels to prevent severe flooding.
Alta Loma rests on the Cucamonga-Sierra Madre Fault. It is a thrust fault, meaning the sides of the fault push toward each other. Several other faults pass through the area, too, including the San Andreas Fault system, of which most of the area’s faults are a part.
Alta Loma Zip Code 91701