Accurate clock synchronization is essential in the operation of Sensor Networks. Algorithms for clock synchronization generally rely on estimators of the relative offset and frequency of two different clocks. Sensor Networks have limited power resources so it is important that these estimators not be too computationally intensive. For this reason a number of least squares-based estimators have been proposed, however they are not appropriate for sensor networks with significant propagation latency. For these applications, the Time Synchronization for High Latency (TSHL) protocol was developed. We seek to improve the accuracy of TSHL and thus propose, study, and demonstrate the effectiveness of several alternative least squares-based estimators.