I agree that there's nothing about "Indian land" at the Jenks Riverwalk or any of the casinos that makes it prohibited carry in Oklahoma statute based on that fact alone. They may have rules about it, but I think that's all they would be considered by those who prosecute.
I might, however, have some concern about a casino because of this:
TITLE 21 § 1272.1 CARRYING FIREARMS WHERE LIQUOR IS CONSUMED A. It shall be unlawful for any person to carry or possess any weapon designated in Section 1272 of this title in any establishment where low-point beer, as defined by Section 163.2 of Title 37 of the Oklahoma Statutes, or alcoholic beverages, as defined by Section 506 of Title 37 of the Oklahoma Statutes, are consumed. This provision shall not apply to a peace officer, as defined in Section 99 of this title, or to private investigators with a firearms authorization when acting in the scope and course of employment, and shall not apply to an owner or proprietor of the establishment having a pistol, rifle, or shotgun on the premises. Provided however, a person possessing a valid handgun license pursuant to the provisions of the Oklahoma Self-Defense Act may carry the concealed or unconcealed handgun into any restaurant or other establishment licensed to dispense low-point beer or alcoholic beverages where the sale of low-point beer or alcoholic beverages does not constitute the primary purpose of the business.
This statute has always been somewhat vague in regard to who/what decides the "primary purpose" of the business. While I don't for a minute believe that the sale of low-point beer or alcoholic beverages is the primary purpose of a casino, I do believe an argument could be made that this rule applies based on the percentage sales of goods there that are alcohol or low point beer. (Gambling is their main source of income I'm sure, but that's not an item that's "sold" and of the items that are sold alcohol and low point beer is probably a fairly significant percentage.)
Carrying a gun around alcohol can be tricky situation dependent upon who is interpreting the law and filing charges. I personally know a CLEET certified armed security officer who took a gig working an after-hours stripper party that was being held at a private warehouse. The party apparently had an unlicensed bar. ABLE got wind, investigated, shut the party down and started handing out charges. This guy had nothing to do with the party itself but ended up getting charged with a felony in violation of TITLE 21 § 1272.1 for carrying a weapon "where alcohol is served." I kid you not. I never thought for a minute the charges would stick if he fought them but rather than risk getting a felony he plead out to some other misdemeanor charge.
