Actually this was his first mountain bike race. He used to do it more and then he took a break from cycling for a while and in the last year or so he's been getting back into it. He has a road bike, but he likes to borrow friends' mountain bikes and play around some. He'd like to have his own mountain bike, but the equipment is so expensive and it isn't in the budget right now.
Cycling widow is right. When he started cycling again I thought it would be so much better than skiing or golf where he's gone all day long. How naieve was I? At least if he's skiing or golfing I can get in touch with him. But it's something he loves to do so I have a hard time complaining too much.
Good luck to your DH. It sounds like he's got a long weekend ahead, but I'm sure he'll have a great time.