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Uncontrolled grazing exacerbates climate-warming effects on riparian soil functions. Temperature is an important driver of evapotranspiration and decomposition and therefore can be a sensitive indicator of management effects on soil water storage and loss. Beginning in 2015, soil temperature was monitored early spring through late summer inside and outside six long-term grazing exclosures (8 to 30 years old) in herbaceous riparian wetlands in the headwaters of the Sweetwater River, Wyoming. This area is part of a large, multi-permittee allotment administered by the Bureau of Land Management and was subjected to season-long grazing for many decades. Sensors installed at 3-, 20-, 40-, and 60-cm depths recorded soil temperature at two-hour intervals from May to August in 2015 and from February to August in 2016 and 2017 at three locations inside and outside of each exclosure. Results indicate consistent differences inside and outside exclosures across years and at each depth. Temperatures were slightly cooler outside exclosures in February, March, and April, then significantly warmer outside than inside across all depths from May through August. Averaged across locations, August soil temperatures differed the most between inside and outside exclosures, with inside temperatures ranging from 15.2 degrees C at 3 cm depth to 11.9 degrees C at 60 cm depth, compared with outside temperatures of 16.8 degrees C at 3 cm depth to 13.4 at 60 cm. The largest difference occurred at 40 cm depth, averaging 1.68 degrees C warmer outside than inside exclosures. The largest temperature differences occurred in August at 40 cm in the 30-year-old exclosures, ranging from 2.5 to 4.5 degrees C warmer outside than inside exclosures. Soil warming is part of a complex feedback relationship among surface residues, plant community composition and productivity, evapotranspiration, and organic matter mineralization that results in less water storage and summer release to downstream aquatic systems.