Bear Brook is a tributary

Tributary

A tributary or affluent is a stream or river that flows into a main stem river or a lake. A tributary does not flow directly into a sea or ocean...

 of Pascack Brook

Pascack Brook

The Pascack Brook is a tributary of the Hackensack River in Bergen County, New Jersey in the United States. It forms a region known as the Pascack Valley. The brook is dammed to form the Woodcliff Lake Reservoir in the town of Woodcliff Lake...

 in New Jersey

New Jersey

New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...

. It joins with the Pascack at the Woodcliff Lake Reservoir

Woodcliff Lake Reservoir

Woodcliff Lake is the name of a reservoir in Woodcliff Lake and portions of Hillsdale and Park Ridge, in Bergen County, New Jersey. It was created circa 1903 by damming the Pascack Brook and is also fed by the Bear Brook which joins the Pascack at the reservoir...

 and forms part of the border between Park Ridge

Park Ridge, New Jersey

Park Ridge is a borough in Bergen County, New Jersey, United States. Park Ridge had a population of 8,645 as of the 2010 United States Census....

 and Woodcliff Lake

Woodcliff Lake, New Jersey

Woodcliff Lake is a borough in Bergen County, New Jersey, United States. As of the 2010 Census, the borough population was 5,730.Woodcliff Lake is also the name of the reservoir that lies primarily within the borough, with a small part of it located in neighboring Hillsdale.The borough is an...

 . The brook flows through portions of Bergen County

Bergen County, New Jersey

Bergen County is the most populous county of the state of New Jersey, United States. As of the 2010 United States Census, its population was 905,116. The county is part of the New York City Metropolitan Area. Its county seat is Hackensack...

 in New Jersey and its headwaters lay in Rockland County

Rockland County, New York

Rockland County is a suburban county 15 miles to the northwest of Manhattan and part of the New York City Metropolitan Area, in the U.S. state of New York. It is the southernmost county in New York west of the Hudson River, and the smallest county in New York outside of New York City. The...

, New York

New York

New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

. 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

Native Americans in the United States

Native Americans in the United States are the indigenous peoples in North America within the boundaries of the present-day continental United States, parts of Alaska, and the island state of Hawaii. They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as...

artifacts have been found.