Paleoclimatology is the study of climates that predate recording technology. The scientific community is interested in paleoclimatology as a means of understanding global climate patterns and predicting future events, especially in the face of anthropogenic global warming. Climate records exist in proxies such as ice cores, sediment cores, tree rings, and speleothems. Researchers analyze these proxies for their isotopic composition among other factors which provide insight into the climate at the time of formation. This study concentrates on the use of speleothems as a paleoclimate proxy. Speleothems are particularly valuable because researchers can determine their absolute age through radiocarbon and U-series dating. Speleothems form when rainwater percolates through soil, dissolves carbonate rock, and precipitates in a cave as calcite or aragonite, both CaCO3. Speleothems record fluctuations in isotope ratios like δ18O and δ13C, both of which give insight into different aspects of climate at the time of formation. Oxygen isotopes in speleothems are related to ice age cycles, moisture source variability, isotopic composition of the moisture source, condensation temperature, and precipitation amount. Carbon isotopes are related to surface vegetation type, the source of CO2 in the soil, bedrock composition, solution residency time, and more. I used a New Wave Research Micromill to collect samples from a Peruvian speleothem that is estimated to have grown between 381,015 and 383,489 years ago. I will analyze these samples for their isotopic composition using a Thermo Gas Bench II connected to a Thermo Delta Advantage mass spectrometer provided by the Union College Geosciences Department. This data will provide insight into fluctuations of the South American Summer Monsoon system and the historical Peruvian climate. We can use this information to understand and mitigate the impacts of anthropogenic climate change in the Andes.