Historic wooden structures in Polar Regions are being adversely affected by decay fungi and a warming climate will likely accelerate degradation. Fort Conger and the Peary Huts at Lady Franklin Bay in northern Ellesmere Island are important international heritage sites associated with early exploration in the High Arctic. Fort Conger, built by Adolphus Greely and expedition members during the First International Polar Year in 1881, was dismantled and used by Robert Peary and his expedition crew in the early 1900's to build several smaller shelters. These historic structures remain at the site but are deteriorating. This investigation examines the fungi associated with wood decay in the historic woods. Soft rot was observed in all 125 wood samples obtained from the site. The major taxa found associated with the decayed wood were Coniochaeta (18%), Phoma (13%) Cadophora (12%), Graphium (9%), and Penicillium (9%) as well as many other Ascomycota that are known to cause soft rot in wood. Micromorphological observations using scanning electron microscopy of historic wooden timbers that were in ground contact revealed advanced stages of type I soft rot. No wood destroying Basidiomycota were found. Identification of the fungi associated with decay in these historic woods is a first step to better understand the unusual decomposition processes underway in this extreme environment and will aid future research to help control decay and preserve this important cultural heritage.