Lake sediment collections, stored at room temperature and freeze-dried, may still be useful for genetic analytical techniques despite the strict protocols that usually accompany genetic analyses. We tested this idea using a surface core from Webster Lake, looking for evidence of increasingly degraded genes with sample depth in the core, and mixing of genetic material across sample depths. We found that none of the 10 samples we provided, from 1-10 cm sample depth, are overwhelmingly composed of the genetic material from the core surface, nor are their genes too degraded for high quality sequencing. We find genetic evidence of harmful algal bloom types, especially in the upper sediments. This finding opens the door for previously collected sediments from many other lakes to be re-assessed using genomic methods to identify the particular species of cyanobacteria in historical blooms.