Hi, this is my first post after hanging arround for quiet a while.
I have got a flight booked through BA Reservations (old fashioned, on the phone

) I will fly from MAN via LHR to Denver on BA and further to Missoula, MT on UNITED.
A few questions:
-Will I have a boarding pass from MAN through to MSO or do I have to check in again in DEN?
-Similar: Will my luggage be checked trough to MSO, or do I have to pick it up and check in again?
- Where will US-Immigration take place? At my final destination at at the point of entry to the US?
Thank you for your help.
Kevin