Is this legal? It seems shady to me

So my husband works at an office that is a satellite of another office. They have about 20 all over the state. The main office is about 2.5 hours north of where we live and work. Tonight he was required to attend the MANDATORY Christmas party up in the town 2.5 hours away from us. And on top of that, they said they won't reimburse anyone for gas money. They're requiring the whole office to come. How is this even legal??? 1. It's a party to celebrate a religious holiday. 2. It's mandatory, shouldn't they have to reimburse for gas money since it's so far away? He doesn't want to make waves because his contract is up for renewal this month and we need this job but it irks me. Sorry, gotta post anon, he needs that contract renewed lol...not taking any chances, it's a big company.