A meticulous field study from 1959 that documented the mammalian inhabitants of Grand Mesa, Colorado, one of the highest and most ecologically distinct flat-topped mountains in North America. Sydney Anderson and researchers from the Museum of Natural History trekked through this isolated montane island, cataloging 22 species of shrews, voles, rodents, and larger mammals while observing five additional species in their high-altitude habitats. What emerges is more than a species list: it is a snapshot of ecological relationships in a landscape that stands apart from the surrounding lowlands, with detailed notes on reproductive conditions, habitat preferences, and behaviors that had rarely been documented at this elevation. The research extended known ranges for several subspecies westward, contributing to our understanding of how life adapts to extreme montane environments. Though nearly seven decades old, this work remains valuable as a historical baseline for tracking changes in mountain ecosystems and for anyone drawn to the quiet scientific work of understanding how wild creatures survive above 10,000 feet.
