To facilitate investigations of flow dynamics in unsaturated fractured rocks, we have designed a probe to qualitatively monitor saturation changes in borchole environments. This flexible probe is able to fit the cylindrical shape of boreholes and requires no backfill. Field results suggest that the design of this electrical resistivity probe (ERP) is suitable for determining changes in relative wetness along boreholes in unsaturated fractured rock environments. The performance of these probes was compared with that of psychrometers under a variety of tests; these probes were found to be significantly cheaper in addition to providing data that had a greater spatial and temporal resolution.