[Highland Park] where to get dirt?

Hi folks, My husband and I want to start doing some gardening in our backyard. We want to put in raised beds, but we're looking at needing on the order of ~6 cubic yards of good topsoil. It seems silly to try to buy that much in bags at Home Depot, but we haven't had much luck locating a local nursery that delivers soil. Does anyone have any suggestions on where we can look? thanks, Rachel