A second-round pick in the 1977 draft, Beeson was named to the PFWA All-Rookie Team and finished second in Defensive Rookie of the Year voting after recording a team-leading 134 tackles, kicking off a productive career in Seattle.  

Over the course of five seasons with the Seahawks, Beeson started 67 games, and he led the team in tackles for three straight seasons from 1977-1979. Beeson’s 1978 total of 153 tackles stood as a single-season franchise record until Bobby Wagner broke it in 2016, and Beeson’s 18-tackle game in 1977 was also a team record that was later eclipsed by Wagner and Jordyn Brooks in the same season.