In Oklahoma, one may register as a Democrat, an Independent or a Republican. You may also choose not to join a party and select the “No Party” option. However, because Oklahoma has a closed primary system, meaning you may vote only in the primary for the party in which you are registered, registering as anything but a Democrat or Republican means you may not be able to vote at all in some primary elections. All registered voters may vote in general elections.
For information on political parties in Oklahoma, visit their official websites.