In five years of operation, the league had doubled in size. Bradford won the league playoffs in 2007 and 2008, South Muskoka won in 2009, Deseronto won it in 2010, and 2007 expansion team Elliot Lake Bobcats took home the Russell Cup in 2011.
As of 2011, five of the original teams are still in operation: Bradford, Deseronto (now called the Storm), King (now known as the Lefroy Wave), South Muskoka, and Toronto. Nipissing and Richmond Hill both folded after three seasons, but Nipissing was replaced in 2010 by the Sturgeon Falls Lumberjacks in their hometown.
The league had boasted two teams of foreigner-only teams, Russians on the Shelburne Red Wings (2010-2014) and Americans on the Orangeville Americans (2011-2015). Hockey Canada and the GMHL have always been at odds. In 2007-08, Hockey Canada initiated a policy of a quarantine system on players, officials, and coaches involved with the GMHL. In the Summer of 2008, this was investigated by the Canadian Government and deemed illegal. Despite this, intimidation has persisted. During the 2010-11 season, this situation grew extreme in Shelburne and resulted in the Mayor of Shelburne forcing a sitdown between the town, Hockey Canada, and the GMHL.
As of September 2011, the league is operating in its sixth season with fourteen active franchises and two dormant franchises set to operate in 2012.
For 2015-16, the league is scheduled to have 34 franchises including 11 expansion teams and two teams on hiatus.
On March 11, 2017 the league announced the addition of the Ville-Marie Pirates to the league for the 2017-18 season.
On August 31, 2017 the league announced that the Parry Sound Islanders were taking a leave of absence for the 2017-18 and would be able to return to the league for 2018-19.
On November 22, 2017 the league announced the Fergua Force were removed from the league and would not be allowed to return for the 2018-19 season.