T. Boone Pickens, a Texas oilman who left a lifelong imprint — some might argue thumbprint — as an avid Oklahoma State University booster, died Wednesday of natural causes in Dallas, The Dallas Morning News reported. He was 91.

Pickens grew from a hardscrabble upbringing into one of the country's most powerful businessmen, parlaying energy gambles and hostile corporate takeovers into wealth unimagined by a onetime laborer.

He then set about becoming a lavish Dallas-based philanthropist, but the native of tiny Holdenville, Oklahoma, always kept his roots deep in his beloved alma mater in Stillwater.

"He was," The Morning News assessed, "among the few business elites granted 'dual citizenship' on both sides of the Red River," no small feat in that neck of the woods.

It is with great sadness that we announce the passing of T. Boone Pickens on September 11, 2019. #RIPBoone https://t.co/w6bt9d22GL pic.twitter.com/PhCvOnOpfs — T. Boone Pickens (@boonepickens) September 11, 2019

According to multiple reports, his donations to Oklahoma State in general, and Cowboys athletics in particular, totaled half a billion dollars, almost equally divided between academics and athletics at the university where the football stadium bears his name.

“He was living proof that anything is possible if you’re wearing orange,” athletic director Mike Holder said in part in a statement.

With his money, however, came his sometimes unsolicited opinion on Cowboys teams, most specifically the football team.

When coach and fellow Okie Mike Gundy's program by Pickens' estimation underperformed (which, frankly, hasn't been often given the arc of the Cowboys' gridiron history), Pickens wasn't shy about sounding off — and leaving a lasting impression..

“We have essentially created a monster that now you have to feed,” Gundy told Bleacher Report in 2017, adding his favorite "Boone-ism" that has served as a guide in that effort: “A fool with a plan can outsmart a genius with no plan any day.”

That kind of folksy approach to life and business guided Pickens to millions in the 1980s that he parlayed into billions in a life that, The Morning News noted, Hollywood producers would have been hard-pressed to exaggerate.

Married and divorced five times, Pickens had five children, 11 grandchildren and three great-grandchildren.