Police say witness accounts tell them the boy possibly hit a bump preventing him from stopping the sled before going underneath a chain link fence and falling down a retaining wall.
The victim who was alert and conscious was transported to Morristown Memorial Hospital.
Chief Spitzer said of the incident, "An eleven year-old boy was sleighing down a steep slope that ended at a fenced-in retaining wall. Because of his speed, and because he was prone, he hit the chain link fence and slid under. He fell approximately twenty to twenty-five feet and struck a tree. Although he was conscious and crying he was transported to a hospital for an evaluation for head trauma and internal injuries, we are all hoping for the best."
Officials posted a no sledding sign after the accident at the scene.