Hello and thank you for using Just Answer.
I have come across this situation many times and with many states.
Oklahoma income tax generally must be withheld from wages paid to resident employees for services performed either within or without the state and from wages paid to nonresident employees for services performed in the state. Your duty station is the reasoning behind the tax liability to Oklahoma. All income you receive while assigned to Oklahoma will be subject to Oklahoma withholding. This is not to say they can keep all the withholding. You will need to file a Non Resident Return for Oklahoma.
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