Acme Planimeter – http://acme.com/planimeter/ – A planimeter is real life tool used to measure acreages on specifically-scaled maps. 

GMap Pedometer – http://www.gmap-pedometer.com/ – Like the planimeter, this tool lets you measure distances on Google Maps. 

Colorado Division of Water Resources Water Rights Map  Homepage:  http://water.state.co.us/ 

Map Viewer:  http://water.state.co.us/DataMaps/GISandMaps/MapViewer/

eRams – https://www.erams.com/ – eRams has a suite of GIS tools.  The Water W.I.S.E. tool lets you create a custom irrigation schedule based on your soils, crops, and irrigation system all based on local data from the CoAgMet station.  You have to create a free account to use the tools.

NRCS Web Soil Survey http://websoilsurvey.sc.egov.usda.gov/  Create customized soil reports for any property.

 Feedipedia  www.feedipedia.org  Database of many forages with information about nutritive value (i.e. Crude Protein, NDF, ash, dry matter, micronutrients, digestibility, etc). 

Colorado Dept of Ag and Consumer Services Weed Fact Sheets –https://www.colorado.gov/pacific/agconservation/noxious-weed-species – A database of all Colorado listed noxious weed species.

USGS EarthExplorer  https://earthexplorer.usgs.gov/  .  Contains many useful USGS products including all archived historic aerial imagery (in some cases back to the 1940s).

Eagle/Garfield/Pitkin County GIS Maps – These counties provide a useful web-based GIS map that allows the public to search for information.  This includes parcel owner information.

Eagle County  http://www.eaglecounty.us/gis/

Garfield County http://garfield-county.com/geographic-information-systems/index.aspx

Pitkin County www.aspenpitkin.com/gis