Holland Township is located in the northwestern part of the County. The Delaware River forms its boundary with Pennsylvania and the Musconetcong River, its boundary with Warren County. It was created from Alexandria Township in 1874. In 1876 it was re-merged with Alexandria Township and separated as a municipality of its own again in 1879. The approximate square mileage of Holland Township is 23.9 and the estimated population is 5,194.
The Musconetcong Gorge Nature Preserve is a rugged undeveloped park under the direction of the Hunterdon County Parks and Recreational System. The Preserve is comprised of 379 acres of steeply wooded terrain overlooking the Musconetcong River. This beautiful gorge includes many spring fed streams, a variety of plant species and wildlife. While the body of the area is a challenge to the seasoned hiker, a diverse trail system is being developed to provide accessibility for the less seasoned hiker.