Species’ occurrence data is becoming more widely available through digitization of museum collections (Hedrick et al., 2020) and citizen science platforms (Dickinson et al., 2012) At the time of writing, the Global Biodiversity Information Facility (GBIF) and Integrated Digitized Biocollections (iDigBio) contain over 1.5-billion records of species occurrences across the planet. Occurrence data is rich with metadata that includes a species name, location, date of collection, and sometimes even photographs of specimens or individuals. The richness of this data allows us to ask questions about changes in biodiversity through time, particularly in taxonomic groups that have not been consistently monitored.The use of occurrence data from museum collections is becoming more common in ecological analyses over the last several years. Importantly, however, improper treatment of these data can lead to misleading inferences (Guzman et al. 2021, Larsen et al. 2021). In this symposium we will present recent advances in methodological approaches that allow us to leverage digitized museum collections. Specifically, we will address how to make inferences about changes in species distributions using occurrence data (Laura Melissa Guzman), how these inferences can be linked to changes in climate (Vaughn Shirey), how we can infer phenology and changes in phenology through time (Michael Belitz), and how we can integrate multiple data sources, such as structured diversity surveys and occurrence data, to make inferences about populations through time (Courtney Davis). Together we tackle methods that ecologists want to use to answer questions about how biodiversity has changed in the anthropocene. References: Hedrick, B. P., J. M. Heberling, E. K. Meineke, K. G. Turner, C. J. Grassa, D. S. Park,J. Kennedy, J. A. Clarke, J. A. Cook, D. C. Blackburn, et al., 2020. Digitization and thefuture of natural history collections. BioScience 70:243–251.Dickinson, J. L., J. Shirk, D. Bonter, R. Bonney, R. L. Crain, J. Martin, T. Phillips, andK. Purcell, 2012. The current state of citizen science as a tool for ecological researchand public engagement. Frontiers in Ecology and the Environment 10:291–297.Guzman, L. M., S. A. Johnson, A. O. Mooers, and L. K. M’Gonigle, 2021. Using historicaldata to estimate bumble bee occurrence: Variable trends across species provide littlesupport for community-level declines. Biological Conservation 257:109141Larsen, E. A. and V. Shirey, 2021. Method matters: pitfalls in analysing phenology fromoccurrence records. Ecol. Lett. P. Early View.