When the Europeans arrived in the area in the 1700s, the Seneca Nation of the Iroquois Confederacy used this area as hunting grounds. In 1757, the Proprietary Council of Pennsylvania sent Moravian missionary Christian Frederick Post to convince the Seneca to join the British in the French and Indian War, but the Seneca sided with the French. The English won the war and eventually purchased the land from the Iroquois.

John Cook was the first permanent American settler. He arrived in 1826 to determine the feasibility of building an east to west canal along the Clarion River for the Commonwealth of Pennsylvania. John purchased 765 acres and settled here with his wife and 10 children in 1828.

At the mouth of Tom's Run, present day Cooksburg, John built his one story cabin and the first of many water-driven sawmills. He worked his mills, logged with oxen, rafted logs to Pittsburgh and also engaged in flatboat building through the years.

John's son, Andrew, bought 36 acres from his father, then gained the rest of his acreage when his father died in 1858. Anthony's industry expanded, and he built the original Cook Forest Inn for his men's living quarters. Anthony erected three sawmills, one flouring mill, one planing mill, a boat scaffold, several dwellings and a store. About 1870, he built the Cook Homestead at the corner of land where Route 36 and River Road intersect. Many of the large homes on River Road are still maintained by the Cook Family and descendents. After Anthony's death, the business was managed under A. Cook Sons Company.

The Cook Forest Association formed in the 1920s to save the few areas of surviving old growth timber. Early pioneers in this effort were M. I. McCreight, Theo Wilson and John Nicholson. The Association, endorsed by national natural resource groups and Governor Gifford Pinchot, raised $200,000.

Publicity such as the following helped raise funds:

" This Wood will become a forest monument, like those of the West, known not only in Pennsylvania, but throughout the Country. The East possesses few scenes more impressive than this magnificent area of primeval white pine, surrounded by giant hemlocks and hardwoods. The venerable splendor of these trees is a heritage for the future of the State. Many of them have lifted their heads to the sunshine of more than two hundred summers and the largest of them were here before the colonization of America..."

Money from the Association helped the Commonwealth purchase 6,055 acres from A. Cook Sons Company in 1927 for $640,000. Cook Forest became the first Pennsylvania State Park acquired to preserve a natural landmark.