Shepherd first gained notice at the 1972 NHRA Springnationals, where he drove a lime green Chevrolet Nova station wagon to the Modified finals and claimed Modified Eliminator honors. That same year he formed a lasting alliance with David Reher and Buddy Morrison after Bobby Cross departed the team. The three Texans pooled limited resources to build what would become one of drag racing's most formidable operations.
The Reher-Morrison-Shepherd team won NHRA Division 4's Modified championship in 1973. A class win followed at the 1974 Winternationals, where Shepherd piloted a Chevrolet-powered F/Gas Ford Maverick through a series of bracket victories and set an F/Gas national record with a 10.39-second pass at 130.62 mph in the final. In 1975, the team transplanted the Maverick's powertrain into a borrowed Chevrolet Corvette body and took another Modified victory at the Springnationals, also claiming Modified Eliminator for the event.
Moving into Pro Stock, Shepherd returned to win the Winternationals twice in that class — in 1980 and again in 1984. The team campaigned a Chevrolet Camaro through its championship years, and between 1981 and 1984 the Reher-Morrison-Shepherd combination won 26 of 56 national events and secured four consecutive NHRA Pro Stock titles.
In 1983, Shepherd became the first driver in history to claim both the NHRA and IHRA Pro Stock championships in the same season. He repeated that dual-championship achievement in 1984, a back-to-back accomplishment that underscored the team's cross-sanctioning authority over the Pro Stock class.
His career record across NHRA competition stood at 173 wins against 47 losses. He reached the final round at 44 national events and won 26 of them, having recorded at least one victory at every NHRA national event on the schedule.
In March 1985, Shepherd was on course for a fifth consecutive NHRA Pro Stock championship when he was killed during a test session in Ardmore, Oklahoma. The cause was attributed to failure of his seat belt and racing harness. At the NHRA Gatornationals — the next scheduled event — Pro Stock qualifiers lined up on the track before eliminations in a missing man formation, leaving the pole position empty in tribute to Shepherd.
In 2001 an NHRA expert panel ranked Lee Shepherd twelfth on the list of the Top 50 Drivers from 1951 to 2000, recognizing his sustained championship dominance and his historic dual-title seasons. He is buried in Mount Olivet Cemetery in Fort Worth, Texas. The Reher-Morrison-Shepherd era remains a benchmark for team organization and mechanical consistency in the Pro Stock class, and Shepherd's career record of four consecutive NHRA titles in one of the most technically demanding categories in drag racing has rarely been approached.