Square tubing behind the front tire.

Do you have a Sasquatch? My guess is, no. In non-Sas trucks, it's a crash bar, to protect the truck's lower extremities (and your feet, I suppose) from the wheel being pushed in/rearwards in a collision. Some mudflap makers (notably RokBlokz) utilize that to hang the flaps from (or on).
It's removed from the Sasquatch trim to accommodate the larger tires' size. I just installed the RokBlokz (which are pricey but worth it), and a hanger is provided in the kit because the crash bar was deleted.

Edit: Use a location on your truck frame for jack placement.