Methane production in Siberian thaw lakes is estimated to be 3.8 Tg CH4 yr -1. When entered into global models, this estimate increases northern wetland CH4 emissions (<6-40 Tg CH4 yr -1) by 10-63% (Walter et al 2006). Methane release of this magnitude from Siberian and other northern lakes, such as those in Alaska, may be linked to the rich carbon resources available to sediment-dwelling methanogens. Researchers posit that methanogens in upper-latitude thermokarst lakes utilize high-quality carbon (C) stocks made available by thaw of permafrost beneath and around the margins of lakes (Walter et al 2006, 2008). The potential for enhanced availability of this C as a result of projected climate warming and associated permafrost thaw makes C source contributions to methane production important to understand. Based on the 14C radiocarbon ages and stable isotope composition of emitted CH4, we suggest that thawed permafrost, made recently bioavailable through the deepening of taliks and/or by thermokarst erosion and deposition of shoreline, supplies labile organic C to anaerobic sediments and drives CH4 production in some interior Alaska thermokarst lakes. We further propose that methanogens utilizing permafrost C also utilize pore water derived from melted permafrost ice as a hydrogen (H) source. In addition to intensive monitoring of two interior thermokarst lakes, this study briefly examines both thermokarst and non-thermokarst lakes along a north-south transect in Alaska, including lakes near Toolik Field Station. Lake surveys reveal large variation in CH4 bubbling rates and bubble gas composition in lakes both similar and dissimilar in character and origin to those investigated in Siberia, and provide a more rounded snapshot of CH4 ebullition dynamics in northern lakes.