Northkill Creek's watershed covers approximately 42 square miles (110 km2) in Jefferson, Penn, Tulpehocken, Upper Bern, and Upper Tulpehocken Townships and Bernville Borough in Berks County and South Manheim and Wayne Townships in Schuylkill County.

[1] That portion of Northkill Creek from its source to the I-78 bridge is designated by the Pennsylvania Department of Environmental Protection as an Exceptional Value stream.

The Pennsylvania Fish and Boat Commission designates Northkill Creek and its tributaries as wild trout streams.

Other significant populations include cutlips minnow, common shiner, eastern blacknose dace, creek chub, and white sucker.

Stream quality is stressed by acid rain (primarily from Ohio power plants), agricultural discharge (nitrates and phosphates), and non-agricultural development (siltation, road salt, animal waste, sewage).

The Hochstetlers, Yoders, Hetzlers and Millers were joined by Zugs, Jotters, Glicks, Kauffmans, and Bishop Jacob Hartzler, and eventually included more than 150 residents.