Outside reason: no one remotely smart agrees.

I have been told that William R. Wade, a mathematician at the University of Tennessee and the author of a well-regarded textbook on analysis, is a young-earth creationist who believes that the evidence supporting the standard scientific view of geology, biology etc. was planted by the devil to test our faith.

My source for this is admittedly not a public one, but note that on his homepage, Wade states that he teaches a Sunday school class in an evangelical church, which should increase the plausibility. (Not all evangelicals are YECs, but most YECs, at least in the U.S., are evangelicals.)