Relitively Humorous
AUTHORS
Patrick McManus
McManus, a humor writer for Outdoor Magazine (he used to write for Field and Stream, but now is the editor at chief (whatever that means) for Outdoor magazine. Interestingly, he's also a professor at Eastern State Hospital, I mean University, in Cheney.

His humor is quite straight forward and almost always focused on the outdoor. My first stories all kind of emulated him in a way.
Garrison Keillor
While most people remember him from "Prarie Home Companion" on NPR, he is also a writer. Unfortunately, I'd much rather sick back and listen to him talk than read his writing - it looses too much in the translation. His mythical place, Lake Wobegon (I tried to find it once on a business trip), is a place I intend to retire to.
Bill Bryson
Author of a "Walk in the Wood", "The Last Continent", "The Sunburned Country" and some other book of short stories that I can't remember the name to.

His most famous is "A Walk in the Wood" is a bit not funny. Quite a bit. Fortunately, the other two are quite good. He launches into some very unique diatribes about the country/personalities/people that, at first, I found as bleak and mean-spirited. However, like moss in the Northwest, they grow on you.
  You can read more about him
here.