San Bernardino County is the largest county in the United States, encompassing over 20,000 square miles. The county is home to stunning natural landscapes, including the majestic San Bernardino Mountains, Joshua Tree National Park, Mojave National Preserve, and the picturesque Lake Arrowhead.

Outdoor enthusiasts can indulge in activities like hiking, camping, and fishing with their dogs.

The best place to stay while exploring this vast area is the Greater Ontario region, which includes the dog-friendly cities of Ontario and Rancho Cucamonga. There, you can experience an abundance of charming tree-lined neighborhoods, parks, historic wineries, and nearby hikes.