Magento 2 extension: Region Manager: Remove/Disable or Change Displayed States and Regions
Region Manager allows handling list of states/regions displayed in the dropdown to your customers. Through user-friendly control panel you can easily exclude unevaluable for shipping and billing areas.
It’s a common issue for Magento stores’ customers to face the list of states (regions for non-US) displayed during checkout, registration, and estimating shipping processes. You can avoid this if you disabled regions in Region Manager administrative panel.