Figure 1. Map of Washington showing county outlines and a 0.1° decimal geographic grid. The 4-digit locality codes in the species accounts refer to 0.1° grid spaces using the abbreviation system described.
Large map (50%, 48k)
Large map (66%, 72k)
Large map (100%, 116k)
From the Introduction: To save space in this checklist, coordinates in each record have been abbreviated to a 4-digit number containing the ones and tenths digits of the latitude, followed by those of the longitude. Thus, 46.3° N, 123.1° W becomes 6331; 48.5° N, 118.7° W becomes 8587. This abbreviation system would be ambiguous if extended beyond the borders of Washington, but it happens that the range of coordinates represented by the state allows no duplication. The records are listed in order, first, from south to north; then, within each tenth degree of latitude, from east to west. Figure 1 shows the state of Washington with county outlines and 0.1° grid lines. Readers are invited to copy this map and plot the distributions of species of interest to them; they will find it surprisingly easy. Any map of Washington showing one-degree lines will allow correlation of grid spaces with towns and other geographic features.