[2] In February 1973, Farrell was hired to replace Al Renfrew as the head coach of the Michigan Wolverines men's ice hockey team.

[4] His best season as the head coach at Michigan was 1976-1977 when the team compiled a record of 28-17-0 (.622) and advanced to the NCAA hockey tournament.

In approximately August 2002, he was a co-founder of Quincy Energy Corp., a uranium exploration company in Hancock, Michigan.

He remained with Quincy as chairman, chief executive officer and a substantial shareholder until July 2006, when the company was acquired by Energy Metals Corp.[12][13][14] Farrell later founded Zacoro Metals Corp. where he served as president and chief executive officer from March 2006 to September 2008.

After Zacoro was acquired by Aura Metals, Inc., Farrell served as the president and chief executive officer of Silver Predator Corp. from March 2009 to December 2009.

[12] He also serves as director of Hy Lake Gold Inc.[12] As of 2010, Farrell was also a Michigan Tech Fund Life Trustee.