Penalties include one year of probation, $8,500 in fines, suspension of the Orange Pride program and university-imposed recruiting restrictions.
"There were mistakes made," said Greg Christopher, who was the NCAA's chief hearing officer on this case and is also the Xavier athletic director. "(But) we didn't believe there was a failure to monitor per se. Because they had a compliance program for a drug policy, they had a drug plan administrator. They had a monitor in place for Orange Pride. The monitoring was there, but it was ineffective."
Oklahoma State will not lose any scholarships or face a postseason ban. The case stemmed from a five-part investigative series by Sports Illustrated into Oklahoma State alleging a series of NCAA violations under coaches Les Miles and current coach Mike Gundy dating to 2001.
The NCAA determined that many of the Sports Illustrated allegations were unfounded after reviewing more than 50,000 emails and other documents and conducting close to 90 interviews of current and former players, coaches, staffers and boosters.
"Some salacious stuff was out there ... a lot of unsubstantiated stuff out there that was not found," Christopher said. "And it was not for a lack of looking. ... We have full confidence in what came out of this."
The NCAA, however, did conclude that from 2008-12 the university violated the NCAA's drug testing policy by allowing five football players to play in a total of seven games when they should have been suspended.
According to the NCAA, Oklahoma State athletic director Mike Holder believed he had latitude in following the drug policy and deferred to coach Mike Gundy's recommendation on whether to suspend players who failed a drug test.
The NCAA also found the school committed recruiting violations through the Orange Pride program.
NCAA rules prevent a school from the use of student hosts in a way that is inconsistent with a university's policies on providing campus tours or visits to all prospective students. Oklahoma State will not be allowed to use the Orange Pride program for four years.
The NCAA also upheld Oklahoma State's self-imposed recruiting restrictions, which included reductions in official visits and off-campus evaluations for the next two years.
Oklahoma State will be limited to 30 official visits per year -- down from 56 -- during the 2015-16 and 2016-17 seasons. It will also reduce the number of coaches participating in off-campus evaluations from 10 to nine in the fall and nine to eight in the spring, and it will reduce the number of evaluation days by 10 in the fall and spring during both years.
"The steps Oklahoma State took from a transparency standpoint should be applauded," Christopher said. "This was really one of the most cooperative investigations in recent history."
The Associated Press contributed to this report.
Oklahoma State on probation for one year
ESPN Big 12 reporter Jake Trotter discusses the NCAA's penalties against Oklahoma State for drug-policy and recruiting violations.