My OCL wrench is somewhere in Big Bend. Did the same thing, laid it on the bumper and drove off. I had large crescent wrench I always carry and it has served me well for the past 2 1/2 years. It works just as well and has other uses, too. I did learn from the experience: don't lay anything on the bumper.
Sid and Becky
2005 Classic 30 "Twinkie II"
2008 Bighorn 4X4 Dodge 2500 Cummins
WBCCI Member At Large #2786
Life is not a dress rehearsal, live your dreams!