Keep from tracking dirt into tent?

[Vincent Peri]

I've been camping now for about 6 years. My wife never goes with me because she doesn't like the bathroom situation and the fact that dirt always gets tracked into the tent floor. She really has a thing for any sort of dirt on the floor, even in our home. Is there a way to keep dirt from getting tracked into your tent? Even putting a mat outside the entrance, dirt always seems to find its way into a tent?