They had menu items marked as gluten free behind the counter and they asked if they needed to clean the workspace to prevent cross contamination. The food was good. And I had a reaction 30 minutes later.
The people at Potato Shack are super friendly and will be able to help you find a potato without gluten. Let them know that it is an allergy and they will take extra precautions to prevent cross-contamination. They also have omission and cider.