Current droughts and increasing water demands are straining water resources in the Salmon River Basin (SRB) and are anticipated to continue in the future. As a robust drought indictor, soil moisture plays an important role in characterizing prolonged droughts. The current study investigate the impacts of two oceanic-atmospheric patterns, i.e. the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO), on soil moisture and identify the most complete driver (PDO/AMO) of soil moisture in the SRB. Using wavelet analysis tools, we found that: 1) soil moisture in both Stanley station (a snow-dominated region) and White Bird station (a rain-dominated region) in the SRB are linked to the variations of the PDO and AMO; 2) both the PDO and AMO have less significant impacts on soil moisture in Stanley station; 3) the PDO produces, with respect to AMO, a stronger correlation with soil moisture in the SRB. Given the importance of the soil moisture to the drought, the results could allow an estimation of drought availability under forecasted oceanic-atmospheric patterns, which will provide useful information for water resources management in the SRB.