In reply to Theho:
I wouldn't try to hire the van and do the drop off. It'll cost ya more than its worth. Fuel alone will be about $100 per day on average and could be more depending on the van. Think 10 to 15 miles per gallon.
What kind of road bikes? Most big centres will have bike hire somewhere. I have a friend who does this out of Canmore though it doesn't look like you'll be that far East.
I don't know enough about California but if ya fancy an alternative, Durango in Colorado is a huge biking place with some serious hills to get up (the rockies).
TBH, I don't think you'll struggle to find something.
As an aside, with 5 weeks I'd definitely divert to Durango and then back into Utah although watch the heat in the desert.
Post edited at 01:20