Here are some links to online environmental resources:

• The U.S. Geological Survey site provides information about "the natural hazards that threaten lives and livelihoods; the water, energy, minerals, and other natural resources we rely on; the health of our ecosystems and environment; and the impacts of climate and land-use change." It is a treasure trove of environmental data.
• Data Science for Dummies recommends the U.S. Geological Survey Science Data Catalog for practicing open data mining, but it also boasts some great educational resources.
• Data.gov offers datasets on climate, ecosystems, oceans, as well as other areas.
• NOAA's Climate Program Office has a Water Resource Dashboard that "provides a 'one-stop shop' for water data needs."
• Check this guide to researching historical weather information.
• The Library of Congress site also has many educational resources from primary sources, including science sources for STEM students, such as Everyday Mysteries and Spotlight on Sports.
• Wild Colorado app lets you identify wildlife as you explore!
• Leafsnap is an electronic field guide developed by Columbia University, the University of Maryland, and the Smithsonian Institution. This free iOS app uses visual recognition software to help identify tree species from photographs of their leaves.