The cub poked its head into the jar while digging through trash.
Biologists say the cub was days away from dying because it couldn't eat or drink.
Rescuers had to tranquilize the mother bear to grab the cub and remove the jar.
The subdued mother was then put in a trap and the cubs followed. After she awoke and nursed the cubs, the bears were moved to a less populated area nearby.
AP contributed to this report.