You have a very good point there. It would have been hard trying to figure out a way to attach a long enough handle to pull anyways. Now to find a cart cheap enough that is only as big to just fit the box onto, I don't want it too big.
ORIGINAL: sticktickler
Sure I always have ideas but to put wheels on the box will make it even heavier for you will need to lift it at some point. You know like getting it in the house or out of the car unless you put a motor on it and drive it to the field and park it in the garage. All jokes aside I'd simply build a cart with caster wheels that the box can sit upon which you can bring to the field. There are many inexpensive hand carts available to buy already made like this one I found see link below.
http://www.uline.com/Browse_Listing_...Handi%2DMovers