Katie, I feel your pain there. I have to drive 2 hours to a Cavenders to get mine. However, you can order them off the internet from either the Wrangler or Cavenders' website.
Even when I do make the trip to the store itself, I can very seldom find more than a single pair, maybe 2 in my size. A woman that wears a 3/4 with a 36" inseam isn't terribly common I guess