The hydration structure around methane hydrate during formation and decomposition has been determined using neutron diffraction with isotopic substitution. Measurements were made over a temperature range of 20 °C to 4 °C and at a constant pressure of 14.5 MPa. The first order difference from the neutron diffraction results suggests that there is an interesting two-stage process to methane hydrate formation that is not evident in the decomposition process. Empirical potential structure refinement (EPSR) of this new data, using the appropriate methane/water weightings for each time segment, confirms an earlier finding that methane hydrate formation increases the diameter of the hydration sphere by approximately 1 Å. In addition, the presence of solvent separated methane molecules is confirmed by the estimated C-C pair distribution function separation of 7 Å.