Campers who show up at Yosemite National Park with scalped campsite reservations may find themselves out of luck and without any place to stay.

Yosemite National Park officials announced Tuesday that they are cracking down on widespread abuses of the reservation system for popular campgrounds in the park.

Starting today, arriving campers will have to show identification to prove they made a campsite reservation.

Campsites in many parts of the park, especially Yosemite Valley, sell out months in advance. Normally, they cost $20 a night. But scalpers using online retail sites such as Craigslist.org sometimes list them for hundreds of dollars. Scalpers also have sold permits to climb Half Dome--something that is issued for free at the park.

In addition to requiring identification upon check-in, Yosemite officials say they will no longer allow the makers of online reservations to change the name of the person for whom it is reserved.

Read more at recordnet.com.