When Bill and Frances Key homesteaded in the rugged Mohave Desert of Southern California in the early 1900s, they couldn't possibly have imagined that a century later, visitors to a national park would be taking tours of their ranch. The tours in Joshua Tree National Park have become so popular that as of January 1, 2011, reservations will be needed for the guided walks.

This year we posted 16 Traveler's Checklists to help you plan your park visits. Did you miss any? Here's a list with handy links.

Are Big Cypress National Preserve officials going too far in support of off-road vehicle interests?

Was the Civil War avoidable? What was the role of the Medical Corps in the Civil War? What weapons were available—and used—by both armies in 1861? Answers to these and other questions will be offered during a winter lecture series at Gettysburg National Military Park to mark the 150th anniversary of the first year of the Civil War.