Concentration data of beryllium-10 from samples collected along moraines in the Beartooth Mountains of Montana, United States for surface exposure dating. Resulting ages constrain the timing of glaciation in a valley from the latest Pleistocene through the Late Holocene including the onset of Neoglaciation and the Little Ice Age. Available data can be used to recalculate ages and uncertainties as well as provide location specific information including latitude, longitude, and elevation of individual samples. Beryllium-10 extraction was conducted at the University of Wisconsin - Madison following methods described in Ceperley (2019). Isotopic ratios of 10Be/9Be were measured on the AMS by PRIME Lab at Purdue University. Exposure ages were calculated using the CRONUS online calculator version 3 (Balco et al., 2008, doi:10.1016/j.quageo.2007.12.001) with the Promontory Point production rate (Lifton et al., 2015, doi:10.1016/j.quageo.2014.11.002) and the LSDn scaling scheme (LIfton et al., 2014, doi:10.1016/j.epsl.2013.10.052). Shielding parameters were calculated from field measurements taken with a clinometer and using the CRONUS topographic shielding calculator (Balco et al., 2008. doi:10.1016/j.quageo.2007.12.001).