Fred Watmough, who is 66, pleaded guilty to assaulting a police officer and was given a conditional discharge, that includes six months probation.
He won't have a criminal record if he completes his probation.
His sons, 30-year-old Kevin Watmough and 28-year-old Allan Watmough, also pleaded guilty to obstructing a police officer and both were granted an absolute discharge.
Last September, the sons argued with police officers after they were told to leave the area that was in the path of the fire around Lethbridge, and when their father arrived, he hit one of the officers with a broom.
The judge says he gave the elder Watmough a conditional discharge because his wife was very ill at the time and died a few days later, and the three were trying to protect their property and crops.
The fire forced about 2,200 people from their homes in several communities, including parts of Lethbridge, until the blaze could be brought under control.
(CJOC, The Canadian Press)