Long-term studies on long-lived species are rare, as is the case for the Alligator Snapping Turtle (Macrochelys temminckii). Here, we developed a database of historical accounts drawing spatial and temporal data from local ecological knowledge (LEK) and non-LEK sources. Across all sources, we compiled 215 spatial and 263 temporal records. To test applicability of LEK, we conducted field surveys at sites selected based on LEK accounts, non-LEK accounts, and habitat. Our surveys yielded occupancy rates of 66.7%, 68.8%, and 40%, respectively, while detectability models estimated proportion of occupied sites to be 58–77%. Catch per unit effort did not vary when compared to previous assessments in Texas. Turtles were most active from February to September. Incorporation of LEK when developing study designs will ultimately enhance communication between researchers and local experts.