This study presents the first shale gas appraisal of Devonian-Mississippian shale strata in Yukon’s Liard basin. Assessed volumes of 68 Tcf gas-in-place and 7.6 Tcf marketable gas are contained within two shale plays identified from an integrated wireline log and geochemical evaluation: the Devonian (Givetian-Frasnian) Horn River shale and the Devonian-Mississippian (Famennian-Tournaisian) Exshaw-Patry shale. Average burial depths of 3018 mTVD and net pay thicknesses of 73 m for the Horn River, and 2688 mTVD and 89 m for the Exshaw-Patry plays are interpreted. Both plays are dominated by black, organic-rich, siliceous mudstones, and exhibit: elevated TOC contents (0.6-6.9 wt %); maturities within or past the dry gas window (2.1-4.6 %Ro); very high biogenic silica proportions (averaging 80.2-90.3%); high mineralogical stiffness (0.80-0.87); and average porosities of 1.2% for the Horn River and 4.2% for the Exshaw-Patry play. Resource distribution models indicate 50% of Yukon’s marketable gas will be found in 30% of its assessed area, with the best potential for significant volumes located in the very southeast of the territory where play depth and thickness increases.