North Temperate Lakes LTER researchers have collaborated with scientists from across the Northern Hemisphere who are interested in temporal and spatial patterns in lake ice phenology. In 1996 a workshop was held at the Center for Limnology's Trout Lake Station. The workshop was attended by an international ad hoc group of scientists who selected the group name Lake Ice Analysis Group (LIAG). One product of these collaborations was a special session at the International Society of Limnology (SIL) meeting in Dublin, Ireland in 1998. Another significant accomplishment initiated at the 1996 workshop was the formation of a database of lake and river ice phenology. The National Snow and Ice Data Center has become the repository for this database that has been periodically updated and expanded. In 2008 a second lake-ice workshop was held at Lake Erken in Sweden with a focus on comparisons of Scandinavian and US Great Lakes Region ice phenology patterns. Both the 1996 and 2008 workshops were funded by grants from the US National Science Foundation associated with the North Temperate Lakes LTER grants.