Data failed to load.
This is a fail-closed state: rather than show an empty or partial map, the app refuses to render until the published dataset loads and its checksum verifies.
Basemap tiles are unavailable (network blocked or offline), so the background street map is missing. This notice speaks only about the street map; each map layer reports its own loading status.

      What this control does to each layer

      Old maps on hand

      Legend

        What the fills and outlines mean

          Photographs

          Photograph layer unavailable.

              Matching this year
              0
              No usable capture date
              0
              Dated past this control
              0
              How to read this layer

                Atlas overlay

                Atlas overlay unavailable. This is an explicit error state, not an empty year: a silently missing overlay would be indistinguishable from "no sheet for this year".

                  Counts

                  0
                  0
                  0
                  0