The active component (e.g., bait or scent lures) common to mammal survey techniques can bias detectability (e.g., aversion or attraction) and reduce their efficacy for spatially explicit, habitat-use research. We overcame this obstacle with 1-m² mud track plots, which use natural ground substrates to sample mammalian species' occupancy with minimal bias of natural movements. Performance of this method was based on criteria that included implementation effort, cost, species detection, proportion of plots to capture tracks, and species identification by track capture. Mud track plots were quickly established, maintained, and monitored with minimal effort and cost. We recorded tracks in 85% of plots over 8 nights, documented all visually confirmed medium and large-sized mammals (>800 g), and captured identifiable (>98%) tracks on a row-crop farm in the Mississippi Alluvial Valley. Drawbacks included limited application for small mammals, potential ambiguity of using track imprints for species identification, and weather-dependent, spatio-temporal restrictions. Mud track plots are an inexpensive, simple approach to noninvasive mammal detection.