Hagerman Fossil Beds National Monument
This park is named for its fossil-producing aspect but it is also an American history park because the Oregon Trail went through the park.
The fossil it is most well-known for is an early zebra-like horse called the Hagerman Horse. One is on display at the visitor center, which is not located within the park itself but in the nearby town of Hagerman. It is a small visitor center but informative. There are also other fossils from the relatively recent Pliocene epoch at the center.
A short drive away, in the park itself, there are depressions called ruts created by wagons traveling the Oregon Trail. Signs tell you that the road leading into the park itself was the also part of the actual trail. There are great views of the Snake River valley from the bluffs that make up the small park. Like many small, fossil-oriented parks, Hagerman is one where you are not likely to run into many other visitors. However, unlike other fossil parks, there is no place other than the visitor center to see the fossils for which the park has gained its notoriety.