In a column published in the October 2016 issue of Scientific American, Steve Mirsky relates his excursion through the Grand Canyon with NCSE.
"Since 1981," Mirsky writes, "the Oakland, Calif.–based NCSE has defended evolution education in public schools against constant threats from those who seek to remove it from biology curricula or to 'balance' it with the addition of oxymoronic 'scientific creationism' or its mutated progeny such as 'intelligent design.'"
Answering the question "what does rafting down the Grand Canyon have to do with science education," NCSE's executive director Ann Reid explained that young-earth creationists have taken the Grand Canyon as evidence of Noah's flood a few thousand years ago, despite the overwhelming geological evidence to the contrary. Mirsky promised to discuss the geologic history of the Canyon in a subsequent issue.
By the way, NCSE is now accepting reservations for the next excursion to the Grand Canyon, June 29 through July 7, 2017.