Bear Brook is a tributary of Pascack Brook in New Jersey. It joins with the Pascack at the Woodcliff Lake Reservoir and forms part of the border between Park Ridge and Woodcliff Lake . The brook flows through portions of Bergen County in New Jersey and its headwaters lay in Rockland County, New York. In Park Ridge, a park named Atkins Glen surrounds a portion of the brook and is home to several shallow caverns, in some of which Native American artifacts have been found.