Deng Kuol Marial ran three seasons (2002-2004) with the cross country team at St. Lawrence College Kingston. During his time at SLC Kingston, Marial won the 2002 OCAA championship and blew past his competition in 2003 earning the OCAA and CCAA gold medals. He was selected as SLC Kingston's Athlete of the Year in 2002 and 2003.

After graduating from SLC Kingston, Marial attended the University of Windsor and competed with the cross country and track and field teams.

Marial was a member of the 2005 OUA championship cross country team at Windsor and represented Canada at the World University Cross Country Championships in Mauquenchy, France in 2008.