The publicity that surrounded the official opening of Kartchner Caverns in November 1999 was in marked contrast to the secrecy that shrouded their discovery 25 years earlier and concealed their existence for 14 years. The two young spelunkers, Gary Tenen and Randy Tufts, who stumbled into what is now considered one of the most spectacular cave systems anywhere, played a fundamental role in its protection and eventual development. Great precautions have been taken to protect
the wet-cave system—which comprises 13,000 feet of passages and two chambers as long as football fields—from damage by light and dryness.
The Discovery Center introduces visitors to the cave and its formations, and hour-long guided tours take small groups into the upper cave. Spectacular formations include the longest soda straw stalactite in the United States at 21 feet and 2 inches. The Big Room is viewed on a separate tour: it holds the world's most extensive formation of brushite moonmilk, the first reported occurrence of turnip shields, and the first noted occurrence of birdsnest needle formations. Other funky and fabulous formations include brilliant red flowstone, rippling multihued stalactites, delicate white helictites, translucent orange bacon, and expansive mud flats. It's also the nursery roost for female cave myotis bats from April through September, during which time the lower cave is closed.
The total cavern size is 2.4 miles long, but the explored areas cover only 1,600 feet by 1,100 feet. The average relative humidity inside is 99%, so visitors are often graced with "cave kisses," water droplets from above. Because the climate outside the caves is so dry, it is estimated that if air got inside, it could deplete the moisture in only a few days, halting the growth of the speleothems that decorate its walls. To prevent this, there are 22 environmental monitoring stations that measure air and soil temperature, relative humidity, evaporation rates, air trace gases, and airflow inside the caverns. Tour reservations are required, and should be made well in advance. If you're here and didn't make a reservation, go ahead and check: sometimes same-day reservations are available (call or arrive early in the day for these). Hiking trails, picnic areas, and campsites ($25 with hook-ups) are available on the park's 550 acres; and the Bat Cave Café, open daily, serves pizza, hot dogs, salads, and sandwiches.
AZ 90, 9 miles south of Exit 302 off I–10, Benson, Arizona, 85602, United States
520-586–4100-information; 520-586–2283-tour reservations