Lake Chelan is the longest and deepest natural lake in Washington, formed by glacial retreat at the end of the last Ice Age. Based on water quality data collected in the 1980s, it is considered an oligotrophic lake and has some of the clearest waters in the state. Because the lake is an important recreational destination and drinking water source there are concerns about the growth of algae in nearshore areas. One species of note is the invasive diatom Didymosphenia geminata (“Didymo”), which was collected in the Chelan River. The goal of this project was to provide information about algae found along the shoreline of Lake Chelan and the Chelan River. The linked report includes an appendix with digital images of the algal taxa identified during the project.