I'm a Canadian and I was pulled over and questioned at a dhs check stop a few years ago, within this 100 mile zone. It all went fine, but the did ask what I was

I'm a Canadian and I was pulled over and questioned at a dhs check stop a few years ago, within this 100 mile zone. It all went fine, but the did ask what I was up to when I went through the same check the next day. (I was sightseeing).