It took the help of a helicopter, but Sierra Nevada bighorn sheep are once again roaming the Great Western Divide that forms part of the border between Kings Canyon and Sequoia national parks.

The money Yellowstone National Park spent this past winter to keep Sylvan Pass safe for snowmobilers breaks down to almost $1,100 per snowmobiler, according to park numbers.

Each Spring, a group of dedicated volunteers and park staff members conduct an annual butterfly count at Joshua Tree National Park to catalog species found inside the park. The park's wilderness areas offer many such opportunities for ongoing scientific discovery, and this year's effort yielded an exciting surprise: a new butterfly species for the park.

There are many wonderful cliff dwellings to see at Mesa Verde National Park in Colorado, and this summer you'll be able to view some not normally open to the public.