[2] The Delaware River has followed a southeast course until now, but after Morrisville in Falls Township it turns approximately ninety degrees to flow southwest.

The canal and park turn southwest earlier and leave the river in Morrisville, cutting off this corner.

It was used to haul coal and other products from the Lehigh Canal beginning in Mauch Chunk (today Jim Thorpe) to the industrial centers of the Philadelphia area near Bristol, Pennsylvania.

From the mid 1950s until 2006, visitors to the park were given the chance to explore the canal in mule-drawn canal boats operated from a landing at Lock 11 in New Hope, and operated north of that point, terminating about 1 mile (1.6 km) north of the Lock 11 landing, near the Rabbit Run and U.S. Route 202 bridges, but was able to navigate all the way to the Virginia Forrest Recreation Area, about 4.5 miles (7.2 km) north of the Lock 11 landing for private parties.

Due to lack of maintenance of the canal by DCNR and floods, the barge concession was forced out of business.

The islands contain archeological clues to the past, provide habitats for migrating waterfowl and songbirds, and offer recreational opportunities in a wild setting for fisherman and canoeists.

The roots of the plants and trees caused the further building of silt and dirt and lead to the formation of the islands.

The cool habitat supports an alpine-Arctic plant community that is very unusual for the latitude of Delaware Canal State Park.

The south facing cliffs in New Jersey at Delaware and Raritan Canal State Park have a nearly opposite habitat.

Sewage and industrial pollution combined with extensive overfishing nearly led to a total collapse of the shad population.

The pollution was so bad that in the years following World War II nearly 20 miles (32 km) of the river was a dead zone, free of dissolved oxygen.

[8] Beginning in the late 1960s, an effort began to re-establish the population of American Shad in the Delaware River basin.

Pollution levels dropped tremendously, and fish ladders were built to allow the shad to bypass the dams that blocked their way and to migrate further up the river.