Foothills are geographically defined as gradual increases in hilly areas at the base of a mountain range. They're generally larger than hills, but not as tall as nearby mountains. Many neighborhoods and communities found in such a location are termed "the foothills". Areas where foothills exist, or areas commonly referred to as the foothills, include: The Foothills of California in San Gabriel Valley in Los Angeles County, California The Colorado Front Range along the Rocky Mountains in Color… (More on Foothills)