Maybe this will help.
TITLE 21 § 1280.1 POSSESSION OF FIREARM ON SCHOOL PROPERTY
B. "School property" means any publicly or privately owned property held for purposes of elementary, secondary or vocational technical education, and shall not include property owned by public school districts or private educational entities where such property is leased or rented to an individual or corporation and used for purposes other than educational.
TITLE 21 § 1277 UNLAWFUL CARRY IN CERTAIN PLACES
D. No person in possession of a valid handgun license issued pursuant to the provisions of the Oklahoma Self-Defense Act shall be authorized to carry the handgun into or upon any college, university, or technology center school property, except as provided in this subsection. For purposes of this subsection, the following property shall not be construed as prohibited for persons having a valid handgun license:
1. Any property set aside for the use or parking of any vehicle, whether attended or unattended, provided the handgun is carried or stored as required by law and the handgun is not removed from the vehicle without the prior consent of the college or university president or technology center school administrator while the vehicle is on any college, university, or technology center school property;
If it is not an elementary, jr high or high school, vo-tech, technology center, or college, then no worries.
You can store a firearm in a vehicle on colleges, universities and tech centers only but not carry on the premises outside of the vehicle.
You can only carry in a vehicle on elementary, secondary schools, or vo-techs, just to drop off or pick up a student and not leave the vehicle unattended.
I'm not a lawyer but this is my understanding of the law.
Here is a link for your own reference.