What branch of government has been instrumental in determining Oklahoma's borders?

The government of the U. S. State of Oklahoma, established by the Oklahoma Constitution, is a republican democracy modeled after the federal government of the United States. The state government has three branches: the executive, legislative, and judicial. Through a system of separation of powers or "checks and balances," each of these branches has some authority to act on its own, some authority to regulate the other two branches, and has some of its own authority, in turn, regulated by the other branches.

The state government is based in Oklahoma City and the head of the executive branch is the Governor of Oklahoma. The legislative branch is called the Legislature and consists of the Oklahoma Senate and the Oklahoma House of Representatives. The Oklahoma Supreme Court and the Oklahoma Court of Criminal Appeals are the state's highest courts.