Fire can change the quality of habitat for many taxonomic groups, including butterflies. The abundance of nectar-producing plants, and the volume and concentration of the nectar in those plants, peaks in the initial years following a fire. Laboratory and controlled experiments have demonstrated that butterflies may have preferences for different sugars in those nectar sources, especially sucrose. However, sugar preferences have not been quantified for an assemblage of butterflies in a field setting. In 2014 and 2015, we conducted butterfly and vegetation surveys within the Rim Fire boundary on the Stanislaus National Forest (Tuolumne County, California). We surveyed eight sites throughout the butterfly flight season in both years and four additional sites in 2015. We analyzed the sugar and sucrose masses, and relative proportion of sucrose, in 20 known nectar sources. We found no evidence that intensity of butterfly use was associated with sugar mass or concentration, mass of sucrose, or the relative proportion of sucrose. Instead, butterflies appeared to use any sources that were available to them indiscriminately...