Our collecting of lichens in Lawrence County, Pennsylvania has increased the known diversity to nearly 50 taxa. Before this study, the most recent published reports on lichens for the county were recorded nearly 60 years ago; hence, many of these records were historic. These aforementioned studies combined with the CNALH database have identified more than 30 taxa that have occurred in Lawrence County which totals 24 lichen species reported for the county. In this study, a collection of nearly 50 lichens were acquired in 2016 and 2017 from Lawrence County. Seventeen lichen species are reported as new to the county. This study demonstrates that lichen diversity in Lawrence County is underestimated.