Bear spray is an effective deterrent when it is quickly accessible. You should carry bear spray in a belt of chest holster. Don’t keep it in your pack or something else that you will set down and walk away from.
If a bear is charging, spray when the animal is about 40 feet away. Spray at a downward angle in the direction of the bear in 2-3 second bursts to create a cloud of irritant between you and the animal.
Do not use the bear spray on yourself or your gear. Bear spray is an animal version of pepper spray, not a repellent like bug spray.
It is not possible to transport bear spray on Alaska Airlines in checked or carry-on luggage. It is sometimes possible to purchase bear spray in Kotzebue. It is also possible to buy it in Anchorage and have it shipped to Kotzebue, but there is an additional cost for hazmat shipping.
When buying bear spray, look for a brand that has a minimum spray distance of 25 feet, a spray duration of at least 6 seconds and is at least 7.9 oz. The Center for Wildlife Information has excellent information about what to look for in bear spray and how to use it.
Always take bear spray with you when you're travelling through bear country.