Will a queen size mattress fit in our whales?

Thought I would ask because I can't find my tape measure. Anybody successful at stuffing a queen size in these wagons?

no
A queen is 60x80. A full size is 54 x 75. Full will still be tight but should work. I would suggest an air mattress or futon as they are more squishable.

Thanks. Wishful thinking that our whales could swallow a mattress whole.

Yes, but it will be sideways and you can't use it. But for transport it will work.
Box Springs I don't know, they don't bend...

The distance between the sides is 48 inches. front to back I believe is 78-84 inches. If the dimensions are within those, you are good to go. You could get a thick piece of memory foam, cut it to fit, and make a cover to keep it from shredding. Even some fairly resilient (firm) seat type foam would work as well. 3-4 inches thick should be sufficient.

I ended up just borrowing my in-laws pick-up. It ended up that it was a memory foam mattress, so I was able to fold it completely in half. It probably would have fit that way, but I didn't realize how flexible it was until we got there. Thanks for all the replies.

This is great, he asks if he can fit a mattress in the back of his wagon and everyone assumes he is trying to sleep in the back.. some of y'all been in trouble with the wife too much.