Fossil Horses of the National Park Service

Every so often I like to do an overview of a fossil group in National Park Service lands. We've had proboscideans, dinosaurs, sloths, and bison, plus late Cambrian and Late Ordovician summaries, and an update to a published packrat midden roundup. This time around, I present Equidae, the horse family. Horses have a long and distinguished fossil record in the NPS, from the Eocene to end-Pleistocene Equus, the modern horse genus. (Note: if this was a formal setting, I'd stick to "Equidae" and "equids" throughout, but I think we can get away with "horses" here.) Cue the map with giant caption:

Another in the long line of long captions. There is some question about the location or antiquity of the records for 30, 31, and 32, so they are marked with gray question marks. 1. John Day Fossil Beds National Monument; 2. Nez Perce National Historical Park; 3. Hagerman Fossil Beds NM; 4. Yellowstone National Park; 5. Fossil Butte NM; 6. Great Basin NP; 7. Golden Gate National Recreation Area; 8. Death Valley NP; 9. Tule Springs Fossil Beds NM; 10. Mojave National Preserve; 11. Lake Mead NRA; 12. Glen Canyon NRA; 13. Grand Canyon NP; 14. Santa Monica Mountains NRA; 15. Joshua Tree NP; 16. Bering Land Bridge NPRES; 17. Kobuk Valley NP; 18. Wind Cave NP; 19. Badlands NP; 20. Agate Fossil Beds NM; 21. Niobrara National Scenic River; 22. Carlsbad Caverns NP; 23. Guadalupe Mountains NP; 24. Big Bend NP; 25. Waco Mammoth NM; 26. Padre Island National Seashore; 27. Mammoth Cave NP; 28. Potomac Heritage National Scenic Trail; 29. Valley Forge NHP; 30. Chesapeake and Ohio Canal NHP; 31. Piscataway Park; 32. George Washington Birthplace NM; 33. Cumberland Island NS; 34. Big Cypress NPRES.