You can park your car for $10 in a parking garage near the Hoover Dam. You can also drive over the dam (to the Arizona side) and park your car for free on a few small parking fields. Parking here is limited, so you either need to be lucky or arrive early at the Hoover Dam. If you're coming in an RV, you cannot park in the parking garage. Instead, you must drive over the Hoover Dam and park it on the Arizona side. A map of all parking facilities can be found on the Bureau of Reclamation's website. This map also indicates whether parking is free or paid.