Above us on a warm spring day, the early jonquils are blooming and trees are just beginning to bud. But where I'm at, some 500 feet beneath the earth motoring quietly along Myst'ry River in Bluespring Caverns, the only form of life in the high-vaulted limestone passageways are strange albino crayfish said to have lived here for eons and a few bats said to live in the ceilings above.
The river winds through subterranean passageways whose sides are edged with sculpted walls dotted with ledges and dark holes leading into deeper passages. The strangely beautiful and surreal stalactites and stalagmites formed slowly by endlessly dripping water.
Our hourlong boat tour traverses just a few miles of this river, the longest navigable underground river in the U.S. Although it's currently measured at 21 miles with much more still to be explored and mapped, our trip covers just a few miles. When the boat turns around, blocked from going farther by monolithic formations, I glance backward and watch it flow on into the dark.
Underneath the rolling hills of Southern Indiana is a complex system of caves thought to number more than 2,600. Only four are easily accessible and open to the public, and each is unique and wonderful in its own way. I find this out as I explore another: Marengo Cave, a tourist attraction since 1883. That's when 15-year-old Blanche Hiestand convinced her 11-year-old brother, Orris, to scramble down a sinkhole and crawl into the small opening of a cave, their only light coming from the two candles they carried.
Now fortunately an expert in cave lighting has creatively disguised lights, something I don't catch on to until our guide points out that a small dripstone formation is really a light. Easily navigable walking trails take us through large cave rooms with names such as Crystal Palace and the Gothic-looking Music Hall with its twisted, intricately water-carved rocks. Here we sit on stone benches, listening to music while watching lights cast the cave's contours in myriad colors.
The tour takes us past two underground lakes — Looking Glass and my favorite, Mirror Lake, because when you look into its placid waters, the reflection of the cave creates the illusion of another room far below.