Alaska Stat. § 03.35.050
The owner of any land within a controlled livestock district may impound a domestic animal trespassing upon that land and keep the animal until damages, together with reasonable charges for keeping and feeding it, are paid. Within 24 hours after impounding an animal, the person impounding it shall give notice in writing to the owner or claimant of the animal, if the owner is known, or, if the owner is unknown, file a notice of impounding with the district judge for the district and post a copy of the notice in a public place nearest to the enclosure of the impounded animal. If, within five days after receipt of the notice of impoundment or posting of the notice of impoundment, the owner or claimant fails to claim the animal and pay the reasonable charges for keeping and feeding it, together with damages and costs, the animal may be sold at public auction as provided in AS 03.35.055.
AS 03.35.050