First a notice I photographed in Joy, Alaska while cycling the Dalton Highway:
http://www.mvermeulen.com/dalton/big/overview_04.jpg
I've done what others have done, in keeping my food and bicycle parked away from where I was sleeping. Some campgrounds had lockers but one in the Yukon Territory (between Haines & Haines Junction) didn't have lockers when I visited. I briefly thought about keeping my panniers in one of the bear-proof trash cans but decided against it under risk of having them accidentally get thrown away. That evening something slashed open a pannier and spent a good amount of effort trying to get into a plastic jar of peanut butter. I suspect it was a bear but not 100% certain. Safety pins are useful to have to hold the pannier back together.
When cycling across the US/Canadian border, I've had Canadian border agents ask me if I was bringing in "any weapons" including asking if I was bringing in bear spray. I never had bear spray with me but I sometimes got a mixed message from those border agents of "do not bring bear spray across the border" with a "you may be crazy to cycle in the Yukon without bear spray...". Personally, I don't particularly want to get close enough to bears to have to worry about bear spray.