PS Forgot to mention -
Another option is to fly to Prince George (YXS). It takes about 90 minutes to drive from Prince George south to Quesnel.
If you fly to YXS you've got some more 'mainline' carriers to choose from, such as Air Canada's regional airline called "Jazz":
http://www.pgairport.ca/yxs/flight/airlines.php
Flying into YXS allows you to build an itinerary on expedia using United & AC, all on one ticket.
Cheers,
Geoff Glave
Vancouver, canada