The objectives of this project are to lay the requisite groundwork, in collaboration with industry, for the rapid development of a commercial microhole logging capability once the feasibility of deep microhole drilling is firmly established. The following technical approaches were adopted by Los Alamos to achieve the technical objectives: -Review and select from existing conventional technologies, or modest modifications thereof, geophysical logs for which the microhole environment offers the most advantage, -Examine the technological feasibility of miniaturizing these logging tools for use in microholes and document the technology challenges in doing so, and -Assess the operational feasibility of microhole logging through the fabrication and deployment of simplified prototypes of selected logging tools.