New Delhi, Nov. 22 -- The alligator was approximately 8ft, lying motionless in the dappled shade of a bald cypress whose roots plunged into the green waters of the Atchafalaya Basin. Captain Mark, our guide from Cajun Customized Excursions, cut the engine of his boat to a murmur and let it drift closer. The gator tracked our approach with the bored menace of a species that has survived 200 million years by practising patience.

"He knows I'm not bringing snacks," Mark drawled. "These gators, they're wild. Not like those tourist ones that come running when they hear a boat engine."

This distinction mattered. We'd driven from Dallas specifically to see the Atchafalaya in Louisiana in its natural state. Mark and his wife Peggy love this wil...