We also checked our bag thru from LAX to Tromso. However you will need to collect your bags in Oslo and pass thru customs. Kinda of a joke as there was not one watching or any look at passports. We pick up bags got them up to the first floor where departures is and then checked in and gave them our bags. They left the tags that were LAX-FRA-OSLO-Tromso on them. It took a few minutes but it is a small terminal and went quickly.

We went to bed early and got up early. Looks like it might be an ok day.