A small population of dwarf palmetto (Sabal minor; Arecaceae) was described in 2011 from Beavers Bend State Park, Oklahoma, approximately 40 km farther north than the species had previously been known to occur along the Red River. The goal of this study was to determine whether this population's size was changing. A 2.75 ha study site along the Lower Mountain Fork River in Beavers Bend State Park was visited in 2011, 2013, and 2015, and all S. minor encountered were marked with a GPS with submeter accuracy. The stage of each S. minor encountered was recorded as either seedling, split leaves, or palmate leaves. Over the course of the study, the number of individuals with palmate leaves increased from 22 in 2011 to 37 in 2015. This increase was mirrored by an increase in the number of seedlings (N = 61 in 2011 and N = 173 in 2015) as well as an increase in the number of individuals with split leaves (N = 9 in 2011 and N = 59 in 2015). The increase of this species at the extreme northwestern edge of its range is consistent with changes in the distribution of other palm species that have been linked with warmer winters. However, the eventual range of this species in Oklahoma may be limited by the availability of water, as the rest of Oklahoma is drier and precipitation across Oklahoma is projected to remain relatively stable.