Travel Reference
In-Depth Information
Most travelers consider spring and fall the best times to visit Big Bend National Park.
Summer (June through August) is very hot, with typical daytime temperatures around
100°F; late summer can be rainy too. Spring means moderate temperatures and lots of
wildflowers (and lots of people), and fall is also quite pleasant, especially for white-water
rafting.
Some park-fanciers believe winter is the best time of all to come; it's usually relatively
mild, although temperatures in the Chisos can fall below freezing and Basin Rd typically
closes two or three times each winter, sometimes for several days. But the snow is never
deep enough to preclude hiking, and the touch of frost makes the trees and cacti a beauti-
ful sight. At all times of the year, it's wise to layer your clothes in the morning and peel
off the top layers as you warm up.
BEAR IN MIND…
There's a slim chance you'll encounter a black bear in the park. If you do, don't run away; instead make lots of
noise and look as big as possible by waving your hands above your head. If you see cubs, back away slowly so
the mother won't fear an attack. To keep bears from joining you for dinner, store all food, coolers, cooking
utensils and toiletries in the trunk of your car or in the special bear-proof lockers, and discard trash in the bear-
proof containers provided at campsites and near trailheads.
Geology
For millions of years Big Bend lay at the bottom of the sea, part of a trough that extended
into what is now Arkansas and Oklahoma. Over time the sea became shallower and even-
tually disappeared, leaving a wondrous fossil record of marine life and beds of limestone,
both thick (the Sierra del Carmen and Santa Elena formations) and thin (the Boquillas
formation). Once the sea was gone, the dinosaurs took over; Big Bend was especially
favored by pterosaurs, the largest flying creatures ever with a wingspan of 35ft or more.
About 65 million years ago, the Cenozoic era began, and tectonic forces produced the
Rocky Mountains and the Sierra Madre. Volcanic activity followed, spreading ash and
lava over thousands of miles in the region. Increased tensions in the earth's crust created
faulting, dropping the central portion of the park while further elevating the Chisos Moun-
tains. Meanwhile, the Rio Grande carved the great canyons that define the river today.
Sights
