There's a road cut that unearthed the tracks nearly 80 years ago. More recently, the roadway has been closed and is now open just to pedestrians and bikers. There are several signs along the way with information about fossils and the area. There is even a dinosaur quarry where the first stegosaurus was unearthed.
Time Needed: several hours
Difficulty: moderate (easy if you pay to take the shuttle)
Kid Friendly: Yes.