After a tour of Europe, we will be traveling FRA-DFW and clearing Customs. The tour ends in DFW and I made separate arrangements from DEN with a separate booking number. Since it is a totally separate flight, can I get my UA boarding pass and check my bags outside of Customs or do I need to haul all luggage to United flight check-in? I know that I will have to go through security again however I am wondering about the logistics of checking my bags after arrival at DFW. Is there a separate check-in desk for United outside of Customs? The bags cannot be checked from FRA to DEN since it is 2 separate bookings.