There's an amazing range of information available online in map form from the federal government. This presentation by Ryan Mattke, head of the University of Minnesota Map Library, covers some of the most useful sites.
- Aerial maps
- Can search by drawing a polygon- will search for all maps that cover that area.
- Requires a free username and password to download maps.
- Not all maps are orientated with north at the top, but they can be rotated.
- Can bulk download maps and put them together in a mosaic.
- Can search for historical maps, no account required.
- Can search by zip code and limit by date.
- You can download part of a map, but you will lose margin information that can be useful, such as the publisher, purpose of the map, etc.
- Can load multiple maps on the same screen- it automatically scales them correctly-e.g. put together old maps of Minnesota counties to show how the whole Twin Cities looked in the past.
- Has historical maps, but is not being updated, the latest maps are on Topoview.
- Helps determine appropriate land use.
- Can draw a square or polygon, then click on "soil map" tab, and get a report on the soil of that area.
- Can download as a .pdf with map and data.
National Geologic Map Database
- Maps of all sorts of geologic features- bedrock, metals, earthquakes, paleontology, etc.
- Click on "Map catalog" to search.
- Not all maps can be downloaded-several options for those that can. Click on "more info" to download.
More cool mapping tools:
- USGS Streamer- trace rivers upstream and downstream.
- US Census On The Map- shows where people travel going to and from work.
- Climate Mapping for Resilience and Adaptation-drought, heat, etc.
- NOAA Historical Map & Chart Collection-nautical charts.
- Geographic Names Server- find places that don't exist anymore-useful for genealogy-international.
Map searching tips:
- Think about who would create the data and why-city, county, country.
- Viewing the attribute table is a good way to figure out what data is included in the data layer.
Check out the slides and try your own searches:
--Andrea H. @GLCL
