Before the NFL banned the open-handed head slap, offensive tackles in the AFL feared Rich Jackson. Originally signed by Oakland as an undrafted linebacker in 1966, Jackson was traded to Denver after his first season. The coaches wisely moved his 6-foot-3, 255-pound frame to defensive end. With a rare combination of quick closing speed and raw strength, he quickly earned the nickname "Tombstone"—because, as teammates said, when he hit someone, they were like heading to their grave.

Between 1968 and 1970, Jackson established a reign of terror, making it one of the most destructive periods for any edge rusher in pro football history. Known for his brutal head-slap move called the "Halo Spinner,” he dominated top-tier tackles like Kansas City's Jim Tyrer and Oakland's Bob Brown, tossing them aside effortlessly. He achieved three straight First-Team All-Pro selections (1968–1970) and earned three All-Star/Pro Bowl honors. Jackson was also the first in franchise history to receive First-Team All-NFL honors after the AFL-NFL merger in 1970. Although sacks weren't officially recorded, film analysis suggests he accumulated approximately 31 to 33 sacks during those three years.

Tragically, Jackson's peak of stardom was cut short at its highest point. During the 1971 season, a serious knee injury sustained against Green Bay severely limited his lateral mobility. He made a brief comeback attempt in 1972 before retiring, leaving behind a short yet undeniable legacy as a formidable game-wrecker. Legendary writer Paul "Dr. Z" Zimmerman regarded him as one of the best overall pass rushers he had ever seen.

In his seven-year NFL career, Jackson played 67 games for Denver, with an unofficial 43.0 sacks and two fumble recoveries. A three-time First-Team All-Pro, three-time Pro Bowler/AFL All-Star, and Second-Team AFL All-Time Team selection, "Tombstone" was enshrined as one of the four first members of the Denver Broncos Ring of Fame in 1984.