San Bernardino County, California, is the largest county in the contiguous United States, covering over 20,000 square miles. It is located in the southern part of the state and is known for its diverse geography, which includes mountains, deserts, and forests. The county is home to several national parks, including Joshua Tree National Park and San Bernardino National Forest, making it a popular destination for outdoor activities. The county seat is San Bernardino, and it has a population of over 2 million residents. It features a mix of urban and rural areas, with cities like Ontario and Fontana contributing to its economic growth. San Bernardino County also has a rich history, with significant Native American heritage and early settlements from the Spanish colonial period.