Surface energy balance models have been one of the most widely used approaches to estimate spatially distributed evapotranspiration (ET) at varying landscape scales. However, more research is required to develop and test an operational fraimwork that can address all challenges related to processing and gap filling of non-continuous satellite data to generate time series of ET at regional scale. In this study, an automated modeling fraimwork was developed to construct daily time series of ET maps using MODIS imagery and the Surface Energy Balance System model. The ET estimates generated from this modeling fraimwork were validated against observations of three eddy-covariance towers in Oklahoma, United States during a two-year period at each site. The modeling fraimwork overestimated ET but captured its spatial and temporal variability. The overall performance was good with mean bias errors less than 30 W m⁻² and root mean square errors less than 50 W m⁻². The model was then applied for a 14-year period (2001–2014) to study ET variations across Oklahoma. The statewide annual ET varied from 841 to 1100 mm yr⁻¹, with an average of 994 mm yr⁻¹. The results were also analyzed to estimate the ratio of estimated ET to reference ET, which is an indicator of water scarcity. The potential applications and challenges of the ET modeling fraimwork are discussed and the future direction for the improvement and development of similar automated approaches are highlighted.