As of May 1, 2010, parking in the lots and parking garage around the Poultry Barn is $5. The lots are cash only; the parking garage (just south of the science museum) also has a credit card option. (Note that due to road construction, it is currently not permitted to turn onto Harley Ave. from University Drive unless you're pulling a horse trailer -- the intersection is marked in red on the map below.)
If you don't mind a brisk walk, free parking is available at the University of North Texas Health Science Center parking garage which is just north of Camp Bowie, near where Will Rogers Road intersects with Camp Bowie from the south (see building #9 on the UNTHSC map); allow about 10 minutes to walk from the garage to the Poultry Barn.
Front View of Poultry Barn (Entrance)
Poultry Barn Back

UNT Health Science Center Parking Garage