Leslie West first gained recognition as the lead guitarist for the Vagrants, a locally popular 1960s Long Island group. One of that group's singles was produced by Felix Pappalardi, a bass player who also produced Cream. After the Vagrants and Cream split up, Pappalardi played bass on and produced West's debut solo album, Mountain (July 1969). Following its release, the two teamed up with drummer Norman Smart (soon replaced by Corky Laing) and keyboard player Steve Knight to form the band Mountain, which cut the albums Mountain Climbing! (February 1970) (a gold-selling LP featuring the Top 40 single "Mississippi Queen"), Nantucket Sleighride (January 1971) (which also went gold), and Flowers of Evil (November 1971). In 1972, Pappalardi left Mountain to return to being a producer.
(Posthumous record releases included Mountain Live (The Road Goes Ever On) [April 1972] and The Best of Mountain [February 1973].) West and Laing joined with former Cream bassist Jack Bruce to form West, Bruce & Laing. The trio recorded two studio albums, Why Dontcha (October 1972) and Whatever Turns You On (July 1973). (A live album, Live 'N' Kickin', was released in April 1974.) Bruce quit in the summer of 1973, and West and Laing briefly formed Leslie West's Wild West Show. Then West, Pappalardi, Alan Schwartherg (drums), and Bob Mann (keyboards) reformed Mountain, recording a double live album, Twin Peaks (February 1974), in Osaka, Japan, in August 1973. This was followed by a Mountain studio album, Avalanche (July 1974) made by West, Pappalardi, Laing, and Knight.
Then Mountain split again, and West formed the Leslie West Band, releasing The Great Fatsby (April 1975) (which featured Mick Jagger) and The Leslie West Band (1976) (which featured Mick Jones, later of Foreigner). Bedeviled by substance abuse problems, West retired from music for a time, then cleared up and again reformed Mountain with Laing and bassist Mark Clarke (Pappalardi had died in 1983) for Go for Your Life (March 1985). The group broke up again, and West made Theme (1988), again teaming with Jack Bruce. West then participated in the Guitar Speaks (1988) and Night of the Guitars recordings of legendary rock guitarists for I.R.S. Records' Illegal subsidiary.
His next solo album was Alligator (August 1989), followed by Dodgin' the Dirt (1994). In 1994, West and Laing teamed with ex-Jimi Hendrix Experience bassist Noel Redding in another edition of Mountain, recording two tracks for the compilation Over the Top (1995). The solo As Phat as It Gets followed in 1999.