My family visited both OU and OK State. They have very different atmospheres. It’s difficult to choose. Both have pros and cons. If you considered attending both, and the quality of the your specific major are about the same at each school, what it was about each one that made you prefer (or dislike
calling @whenhen 
I just returned from an OSU Spring Break abroad class, and go to OU. During that class I spent a considerable amount of time speaking with current Oklahoma State students and faculty and had to twice travel to the campus for pre-course work. I also know a number of students who started at OSU and transferred to OU.
Although OU and OSU are both located in college towns and have quite attractive campuses (Oklahoma State’s is nicer IMO), they feel considerably different, probably due to the different students they attract. My impression of OSU is that it tends to get students from more rural parts of the state, making the overall climate vastly more conservative than OU’s. During the abroad class, the topic of American politics frequently came up since we were visiting one of the last remaining communist nations on Earth. When asked who I supported, the questioner asked if I was pro-Cruz or Trump. That someone would be a Democrat didn’t even register. This could have been a misspoken question, but one of the faculty members told me how few liberals she knew at the school. OU by contrast has a relatively large portion of liberals, although it is still by national standards a center right school.
As mentioned before, Stillwater and Norman are both college towns, but even then there are differences. Norman is only around 30 minutes south of downtown Oklahoma City and is, without question, part of the greater Oklahoma City metro area. Stillwater is not. It is an isolated town with a total population under half the size of Norman. Many OSU students complain there is nothing to do around Stillwater, outside of a few restaurants and the actual university. Though a school with 20,000 people will have plenty to do on campus, I know from experience that on campus events can get very old very fast. Keep in mind that Norman does get boring at times, but for students with a car it is very easy to get into Oklahoma City which has many more entertainment options.
OSU has a slightly lower percent of students in Greek life, but I’d argue that the difference is so slight as to not be noticeable. There are more non white, and out of state students at OU, both in absolute numbers and on a percentage basis, than OSU if that’s important to you at all.
Based on my impressions, the University of Oklahoma is more artistically oriented than Oklahoma State which strikes me as a more technical university. Though there are certainly humanities and visual/ performing arts majors at OSU, they are far less numerous than at OU. OSU obviously has many agricultural students and thus a number of farming related activities.
Thank you @whenhen. I’d prefer a more outdoorsy environment, so choosing one is difficult.
Both will be outdoorsy - but one will also have access to a city (something you might handy not just to hang out on weekends but when you’re a junior looking for an internship.)
Neither school is outdoorsy in the sense that students regularly go hiking, rafting, etc. If you’re looking for that kind of vibe, frankly you’re not going to find it in central Oklahoma where both schools are located.
That being said OU does have a semi-active outdoors club as well as a number of other clubs where students regularly go hiking, sailing, etc. I don’t know what Oklahoma State has, although I do know that Stillwater, like Norman, would never inspire John Muir like proclamations.
^I’m hoping OP doesnt mean it in the Middlebury/Sewanee/Colby sense, because otherwise OK isn’t going to be it.
I know. But, unfortunately, those schools are the only options.