Testing image limits
Here's a 40MByte image. How did it do? Badly, it turns out; there's no obvious way to download the full res image. The actual image is at /wp-content/uploads/2021/01/greenroad_5px_per_foot.png

Edit 2021-07-13 check out this amazing shaded relief from the Arkansas Spacial Data Infrastructure (ASDI) Map Viewer. I monkeyed with the brightness/contrast to bring out the relief shading. Full image at /wp-content/uploads/2021/07/asdi_map_viewer_greenrd.png
