There Gregory Peck discovered him, cast him in La Jolla's production of Goodbye Again, and then arranged for Forrest's first screen test with MGM, where he was signed to a contract.

[1] Among Forrest's notable films were So Big, for which he won the Golden Globe Award for New Star of the Year – Actor, The Longest Day, North Dallas Forty, and Mommie Dearest.

[5] Forrest was also a trained vocalist, and he made his debut on Broadway as boxer Bob Stanton in the 1958 production of the Harnick and Bock musical The Body Beautiful opposite Mindy Carson, Jack Warden and Brock Peters.

Senator William Borah in the 1963 episode "The Lion of Idaho" of the syndicated television anthology series Death Valley Days.

In 1965, Forrest and his family moved to London, where he starred as John Mannering in the title role of the British crime drama The Baron.

They brought him back as a similar character renamed Wes Parmalee, who would be revealed to actually be Jock Ewing, in the 1986-87 season.

In a career that spanned six decades, among films he appeared in were 'Prisoner of War' (1954), 'The Living Idol' (1957), 'Flaming Star' (1960), 'The Longest Day' (1962), 'Rascal' (1969), 'The Wild Country' (1970), 'North Dallas Forty' (1979), 'Mommie Dearest' (1981), 'Sahara' (1983), 'Amazon Women on the Moon' (1987) and 'S.W.A.T.'