Species richness scores for all HUC 12 watersheds that contain historic richness data for California. Each watershed was given a score dependent on the ratio of current richness to historic richness. Scores equaling 100 represent no loss in richness over time or even gains in richness. A score of 50 represents a loss of 50% richness between the historic and current species richness in each HUC12. Absence of a score means that no information is available for historic or current fish distributions in that particular HUC12.