A rescue can come from any source, pet stores, etc, as mentioned beforehand, spca's in your town, just let them know that if a BD comes in, you are available to rescue, craigs list is a great place to find beardies, you may not think of craig's list as a rescue, but many pics show that some people don't know how to care for beardies, and they give them away when they become bored with them and when folks don't buy them.
Another source is Reptile Expo's, believe it or not, massive breeders that don't really care for their young (and you'll be able to pick them out) have alot of handicapped beardies...I remember one baby, she/he looked half dead in the dish, for sale at 120.00, someone was interested in it, so I spoke to the vendor, pointed out the handicaps, etc, and was able to talk them down to 30.00. I was so glad to have this little one get into a loving home (I don't know that the vendor was happy, though)............And of course, there are word of mouth rescues, as well.
So if you really search.....you'll find them.....or better yet......they'll find you.
Best wishes, <><