Born in Philadelphia, DaShiell lived on Oahu between the ages of three and fifteen, and took up guitar at the age of fourteen. He moved with his family to Florida in 1963, where he formed a band that played covers in the local Sugar Shack club He then joined Doug Killmer"s band The Sonics, which after the addition of drummer Rick Jaeger became The Beau Gentry in 1965.
The band evolved into Crowfoot and relocated to San Francisco.
DaShiell also began working as a session guitarist, playing on Bachelor of Arts Skhy"s 1969 debut album, and going on to play in Harvey Mandel"s band. He also played on Norman Greenbaum"s Spirit in the Sky album, including the chart-topping title track, and went on to tour with Greenbaum and play on his next two albums.
His success prompted him to revive Crowfoot, although the band"s self-titled 1970 album was largely a DaShiell solo effort, as was its 1971 follow-up Find the Sun. DaShiell continued with session work through the early 1970s, recording with artists such as Philosophy Everly, Danny O"Keefe, Bo Diddley, John Sebastian, and former Creedence Clearwater Revival member Tom Fogerty, working in the latter"s band with Stu Cook and Doug Clifford, also former Creedence members.
He went on to work with Cook and Clifford on solo material and joined them in the Don Harrison Band, recording two albums in 1976.
DaShiell finally released solo material in 1978 after signing with Epic Records. The Elevator album, featuring his collaborations with Cook and Clifford, was released in 1978. Although his solo career was initially short-lived, he continued to work on various projects, including a single and album with new band "I Spy" in the 1980s.
He also produced a solo album by Doug Clifford.
By the end of the 1980s he had moved into television soundtrack and editing work, notably on In Living Color. In the early 1990s he reformed Crowfoot with former members Doug Killmer and Rick Jaeger, releasing the European Parliament Messenger in 1994.
He composed for advertising while continuing to record solo material, with the albums Foreverland Forest and Island Life released digitally in 2010 via his website spiritguitar.com.