Historical gold mine tailings may have elevated total mercury (Hg) and total arsenic (As) concentrations. We collected and analyzed the fruticose lichen genus Usnea and the foliose lichen genus Platismatia for biomonitoring airborne sources of Hg and As at the historical Montague Gold Mine District in Nova Scotia, Canada. We investigated spatial trends of Hg and As measured from 112 Usnea (10 species) and 113 Platismatia (2 species) lichen thalli collected across four sampling grids covering both tailings and nontailings areas. Usnea consistently had higher Hg concentrations, while Platismatia showed higher As concentrations. Areas where there was evidence of known past mining activities (i.e., mine shafts, stamp mills, Hg-amalgamation sites) were found to be hotspots for both Hg and As in the lichen samples collected nearby. These areas likely received greater inputs of these elements from windblown tailings or volatilization processes, or indirectly from the interception of these elements by the forest edge/canopy adjacent to the tailings. A tailing-contaminated wetland at Montague was also identified as a hotspot for Hg, likely facilitating its redistribution into the atmosphere. Co-sampling of a fruticose and a foliose lichen can be an effective method for airborne monitoring of contaminants around historical mine tailing sites. Keywords: Nova Scotia; Canada; Montague Gold Mine District; Usnea; Platismatia.