To identify appropriate species of ectomycorrhizal fungi for use in the reclamation of saline-alkaline sites, such as the composite tailings (alkaline, with high sodium, sulfate, and calcium) produced by the Canadian tar sands industry, pure cultures of nine fungal species indigenous to the Canadian boreal forest were grown on media containing different levels of CaCl2, CaSO4, NaCl, or Na2SO4, as well as on medium containing composite tailings (CT) release water, and on media at four different pH levels. Members of the Boletales (Suillus brevipes, Rhizopogon rubescens, and Paxillus involutus) and Amphinema byssoides (Aphyllophorales) were sensitive to alkalinity, and their growth was completely inhibited by CT release water. Laccaria and Hebeloma spp. (Agaricales) as well as Wilcoxina mikolae (Pezizales) were tolerant to alkalinity and survived on the medium containing CT release water. Calcium chloride proved to be the most toxic of the salts tested. Growth of seven isolates of Laccaria bicolor and three isolates of Hebeloma crustuliniforme on media containing CaCl2 and release water showed low intraspecific variation. A combination of fungal species, each with its own beneficial characteristics, is recommended for the inoculation of seedlings to be outplanted onto composite tailings.