Predicting responses of semi-arid to montane landscapes in southwestern North America to ongoing anthropogenic changes requires understanding of past interplay among geomorphic, ecologic, and climatic factors. This study utilizes modern weathering and sediment transport processes to inform the interpretation of a 250-kyr lacustrine sediment record of paleoecology, hydrology, and erosion from a small, closed basin, basaltic catchment on the southwestern edge of the Colorado Plateau. Geochemical and mineralogical analyses of bedrock, colluvium, and lake sediments indicate that clastic sediments in the basin are a mixture of local physical weathering products (albite and ilmenite) and eolian dust (quartz, illite, and zircon). Dust fractions increase during glacial periods coincident with lower overall sedimentation rates, suggesting this pattern results from decreased local erosion rates and not increased dust deposition. Titanium counts from X-ray fluorescence core scanning, a proxy for ilmenite content, traces past local erosion rates. The highest erosion rates, inferred from the highest Ti counts, follow climatic transitions toward interglacial conditions (Marine Isotope Stage 5e, 3a, and the Holocene), periods characterized by vegetation changeover (observed in the core's palynology), higher temperatures (pinon-juniper-oak pollen abundance), lower effective precipitation (shallow lake facies), and increased wildfire activity (microscopic charcoal particle counts and sizes). While brief inferred episodes of erosion occur following abrupt transitions to cooler and wetter conditions, indicated by the abundance of subalpine tree (spruce and fir) pollen and deeper lake facies, landscapes appear more stable during glacial periods. This long-term perspective suggests that aridification and resulting vegetation succession and increased wildfires will increase erosion rates in similar settings regionwide. Many humans depend on the dry landscapes of southwestern North America for their livelihood. Identifying potential challenges associated with human-caused climate change in the decades and centuries to come requires us to examine how these landscapes have responded to past changes in vegetation, precipitation, and forest fires. This study focuses on a lake sediment core from a small watershed on the southwestern edge of the Colorado Plateau as an archive of the past 250 thousand years, a period spanning multiple significant climate changes. Taken together, indicators of local erosion, climate, fire activity, and plant communities found in lake sediments demonstrate this landscape is shaped by climate change. While transitions toward wetter and cooler conditions can stimulate erosion briefly, the longest lasting increases in erosion occur following transitions toward warmer and drier conditions with greater forest fire activity. Because these types of environmental changes are occurring today due to human-caused climate change, we expect erosion rates to remain high or increase in similar settings across the region. In a semi-arid landscape, transitions to drier climates cause increases in erosion lasting on the order of 103-104 yearsWildfire activity and pine tree abundance correlate with enhanced erosionAnthropogenic drying trends and increased wildfire in southwestern North America will promote enhanced erosion rates