The US southern Great Plains includes Texas High Plains, the Oklahoma Panhandle, part of eastern New Mexico, southwestern Kansas, and southeastern Colorado. Hard red winter wheat is a major dryland crop in the region. Due to the semi-arid climate with highly variable annual precipitation, drought is the most common abiotic stress during wheat growing season. Therefore, improving drought tolerance is important for sustainable dryland wheat production in the Southern Great Plains. We have conducted field studies on dryland wheat at Bushland, Texas since 2010. The objectives are (1) Understand physiological mechanisms for improved drought tolerance; (2) Identify plant traits conferring drought tolerance; (3) Develop phenotyping tools for screening drought tolerance in the field. Each year, 20 hard red winter wheat genotypes were grown under wheat-fallow-wheat rotation system. The genotypes include a historic check cultivar, new released cultivars, and advanced experimental lines. Dryland wheat yield varied significantly among the years (from 0.67 Mg/ha in 2011 to 4.03 Mg/ha in 2019). Higher yield is generally associated with greater soil water storage at planting and as well growing season precipitation. Yield differences among genotypes were highly significant, and more drought tolerant genotypes can yield 40% more than drought susceptible ones. The newer cultivars or more drought tolerant genotypes had greater biomass at anthesis, more seeds per spike and higher 1000-kernel weight under drought. In addition, drought tolerant cultivars were able to extract more water from deeper soil profile (particularly between jointing and maturity) and maintained cooler canopy temperature than drought susceptible ones. Remobilization of stem carbon reserves also contributed to yield under dryland conditions. We have evaluated different sensors and platforms for field phenotyping. The Unmanned Aerial System (UAS) based platform showed more promise for high-throughput phenotyping under field conditions.