The Oklahoma Department of Corrections says the incident prompted a lockdown at the North Fork Correctional Unit in Sayre, about 120 miles (190 kilometers) west of Oklahoma City.
The agency says authorities arrested Kerri Jo Hickman after discovering the T-shirt gun and another package in her vehicle.
Tulsa television station KOTV reports that the container that was launched Sunday contained cellphones, ear buds, phone chargers, methamphetamine, digital scales, marijuana and tobacco.
Hickman remained jailed Friday in Beckham County on complaints of introducing contraband into a penal institution, conspiracy and drug trafficking. Jail records don't list an attorney who could speak on her behalf.
Copyright 2019 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.