As a senior, he received South Bend Tribune Offensive Player of the Year and All-State offensive/defensive back honors.
In 1983, he played nickel cornerback over former first-round draft choice Rod Hill, while posting 5 interceptions (second on the team).
Fellows was part of an opportunistic Cowboys secondary that earned the nickname "Thurman's Thieves", because of the amount of plays and turnovers they generated.
In 1984, after Thurman made the permanent switch to safety, he became the starter at right cornerback opposite Everson Walls, and posted 3 interceptions.
In 1985, he struggled with a sprained knee he suffered in the first quarter of the season opener against the Washington Redskins, which caused him to miss 3 games and 2 starts, eventually requiring offseason surgery.
On August 2, 1987, after being involved in a contract holdout and the Cowboys needing help at wide receiver, the team felt they had depth at cornerback after drafting Ron Francis, so he was traded to the Los Angeles Raiders in exchange for Rod Barksdale.
[6] Fellows married wife Debra in 2002 and founded the Stars for Life Foundation, a nonprofit aimed at serving Native American communities suffering from addiction, diabetes and suicide.