The extensive methane (CH4) hydrate deposits found in shallow permafrost and continental margin sediment has generated interest as a potential natural resource, a submarine geohazard, and a contributor to global climate change. The significance of gas hydrate in these roles depends in part on the effects of temperature on their stability, and hence can be sensitive to exchanges of heat with their environment. Thermal properties such as conductivity and diffusivity are therefore important properties governing the response of hydrate-bearing sediment to natural or man-made thermal perturbations. We seek to improve characterizations of hydrate's in situ thermal behavior by making laboratory measurements of thermal conductivity in pure sI CH4 hydrate at near in situ pressures and temperatures.