Very often, finding online map services are only a Google search away. In recent years, more organizations are using map services to make their data available to the masses. Below are just a few online resources that offer robust map services.
ArcGIS Online provides a collection of 2D map services and 3D globe service that can be accessed with any ArcGIS application including ArcGIS Explorer, ArcMap, or web mapping applications created with ArcGIS Server.
The Geography Network is a global network of geographic information users and providers. The Network makes dynamic maps, downloadable data, and advanced web map services available to the public free of charge.
The Geospatial One-Stop is a GIS portal that serves as a public gateway for improving access to geospatial information and data. The Geospatial One-Stop provides a variety of ArcIMS map viewers and supports Web Mapping Services (WMS) ESRI ArcIMS services which can be viewed in Google Earth or ESRI ArcGIS Explorer.
Arizona NEMO has put together a set of Internet Mapping Services (IMS) that are viewable in a browser. Click HERE for more of an overview of what's included in AZ NEMO's services and how to use them.
The National Atlas is a Web Mapping Application (WMS) that contains geospatial and geostatistical data for the United States. It can be viewed in a browser or embedded in an application using WMS specifications. The National Atlas Map Maker allows you to assemble, view, and print your own maps. Map layers can also be downloaded in GIS format using file transfer protocol (FTP). See their Raw Data Download page for more information about downloading National Atlas map layers.
The National Map is an Internet Mapping Service (IMS) that can be viewed in a web browser. It consists of a seamless, consistent framework of geographic features for all of the United States. The National Map includes tools for selecting and downloading geospatial data in a variety of formats.
The Integrated Vegetation Map Viewer is an Internet Mapping Service (IMS) that provides a dynamic online map interface that can be used to view a suite of satellite-derived vegetation condition datasets, integrated with information from the National Map. Learn more about it HERE.
The Drought Monitoring Map Viewer is an Internet Mapping Service (IMS) that provides a dynamic online map interface of drought-related geographic information. The interactive map can be used to view satellite-derived vegetation condition datasets, integrated with information from the USGS Center for Earth Resources Observation and Science (EROS).
The USGS Coastal and Marine Geology Program put together an Internet Mapping Service (IMS) site containing geospatial data for Monterey Bay.