In this paper we report laboratory acoustic velocity and electrical resistivity measurements on Berea Sandstone and Austin Chalk samples saturated with a stoichiometric mixture of tetrahydofuran (THF) and water. The and water is an excellent experimental analogue to natural gas hydrates because THF solutions form hydrates similar to natural gas hydrates readily at atmospheric pressures. Hydrate formation in both the chalk and sandstone samples increased in the acoustic P wave velocities by more than 80% when hydrates formed in the pore spaces; however, the velocities sool plateaued and further lowering the temperature did not appreciably increase the velocity. In contrast, the electrical resistivity increased nearly 2 orders of magnitude upon hydrate formation and continued to increase slowly as the temperature was decreased. In all cases resistivities were nearly frequency independent to 30 kHz, and the loss tangents were high, always greater than 5. The dielectric loss showed a linear decrease with frequency suggesting that ionic conduction through a brine phase dominates at all frequencies, even when the pores are nearly filled with hydrates. We find that resistivities were strongly a function of the dissolved salt content of the pore water. Pore water salinity also influenced the sonic velocity, but this effect is much smaller and only important near the hydrate formation temperature.