The temporal variability of soil moisture in the basin was analyzed using the temporal autocorrelation functions calculated for each of the seven HMT observing stations during the study period. The spatial soil moisture variability was examined using correlation coefficients calculated for each possible station data pair in the network. Results from these two procedures indicate that coherent spatial and temporal features of the soil moisture field in the Russian River basin can be inferred from HMT soil moisture observations. The third part of the analysis involved the construction of a covariance matrix from the spatial and temporal differences between the simulated and observed data. A positive definite test on this matrix revealed that it is possible to minimize the difference between the HL-RDHM simulations and the corresponding soil moisture observations from the HMT network. This poster will demonstrate how these analyses have been used to help determine whether or not soil moisture observations can be assimilated into the HL-RDHM, and thereby improve the quality of its soil moisture and streamflow simulations.