The SnapMaps site cooperates with the SnapPlus desktop nutrient management application to produce the maps required for a 590 or NR 243 nutrient-management plan. It can also be used as a standalone website to view restriction map layers.
You can view several instructional videos about SnapMaps on YouTube. The SnapPlus site has a page describing the videos and organizing them into topical playlists.
In cooperation with WI DATCP, the UW-Madison's Nutrient and Pest Management Program has produced a two-page informational handout explaining the terms used for 590 maps. It also contains a detailed legend for the maps.