This collection contains small mammal vouchers collected during small mammal sampling (NEON sample classes: mam_pertrapnight_in.voucherSampleID). Small mammal sampling is based on the lunar calendar, with timing of sampling constrained to occur within 10 days before or after the new moon. Typically, core sites are sampled 6 times per year, and relocatable sites 4 times per year. Small mammals are sampled using box traps (models LFA, XLK, H.B. Sherman Traps, Inc., Tallahassee, FL, USA). Box traps are arrayed in three to eight (depending on the size of the site) 10 x 10 grids with 10m spacing between traps at all sites. Small mammal trapping bouts are comprised of one or three nights of trapping, depending on whether a grid is designated for pathogen sample collection (3 nights) or not (1 night). Only mortalities and individuals that require euthanasia due to injuries are vouchered. The NEON Biorepository receives whole frozen specimens and prepares vouchers as either study skins with skulls (or full skeletons) or in 70-95% ethanol. Standard mammalian measurements are taken during specimen preparation (in mm; total length, tail length, hind foot length, ear length; and in g: mass) and are accessible in downloaded records (note: field measurements are listed in parentheses after preparation measurements, when available). Additional notes about parasites and reproductive condition are also accessible in downloaded records. See related links below for protocols and NEON related data products.