The Laboratory
http://www.cbc4kids.ca/general/the-lab/default.html

Midcontinent Ecological Science Center
http://www.mesc.usgs.gov/

Protist Image Data (PID)
http://megasun.bch.umontreal.ca/protists/protists.html

Neanderthal Museum
http://www.neanderthal.de/

Sandlot Science
http://www.sandlotscience.com/

Science Bob
http://www.sciencebob.com/

Amusement Park Physics
http://www.learner.org/exhibits/parkphysics/index.html

Sport Science!
http://www.exploratorium.edu/sports/index.html

The Globe Science Program
http://www.globe.gov/

National Science Foundation
http://www.nsf.gov/

The Why Files
http://whyfiles.news.wisc.edu/index.html

Mad Scientist Network
http://www.madsci.org/

Exploratorium (Secondary)
http://www.exploratorium.edu/

Extreme Science
http://www.extremescience.com/

Science Learning Network
http://www.sln.org/

The Ozark Mountains
http://www.ozarkmtns.com/spring/index.htm

Exploratorium Science Snacks
http://www.exploratorium.edu/snacks/snackintro.html

CoolScience for Curious Kids
http://www.hhmi.org/coolscience

Science Made Simple
http://www.sciencemadesimple.com/

Natural History Notebooks
http://www.nature.ca/notebooks/english/mon2.htm

NASA Kids
http://kids.msfc.nasa.gov

Hunkin's Experiments
http://www.HunkinsExperiments.com/

Tennessee Science Curriculum Framework (4th grade)
http://www.utm.edu/departments/ed/cece/fourth/4B3.shtml

Earth Floor Cycles (Rock Cycle)
http://www.cotf.edu/ete/modules/msese/earthsysflr/rock.html

Athena
http://vathena.arc.nasa.gov/

American Museum of Natural History
(Endangered Animals)
http://www.amnh.org/exhibitions/endangered/index.html

All About Nature Coloring Books
http://www.allaboutnature.com/coloring/

Solar System & Astronomy

Energy, Biomes, & Earth Science

Animals, Zoos, & Museums

Birds & Insects

eNature
http://www.enature.com/

Zoom Butterflies
http://www.EnchantedLearning.com/subjects/butterfly/

Butterflies at the Field Museum
http://www.fmnh.org/butterfly/

Butterflies of North America
http://www.npwrc.usgs.gov/resource/distr/lepid/bflyusa/bflyusa.htm

National Wildlife Federation for Kids
http://www.nwf.org/kids/

Monarch Watch
http://www.monarchwatch.org/index.html

The Butterfly WebSite
http://butterflywebsite.com/

Insect Identification Laboratory
http://everest.ento.vt.edu/Facilities/OnCampus/IDLab/id/id-main0.html

Wild Birds
http://www.kaytee.com/wild/

All About Birds
http://www.enchantedlearning.com/subjects/birds/Allaboutbirds.html

WildLife Sanctuary
http://ausinternet.com/ettamogah/siteindex.htm

Weather

Hurricane and Storm Tracking
http://hurricane.terrapin.com/

Weather World
http://www.ems.psu.edu/WeatherWorld/kidstuff/kidlinks.html

Weather
http://weather.com/education/

The National Weather Service
http://www.nws.noaa.gov/

Memorable Weather Events
http://ww2010.atmos.uiuc.edu/(Gh)/arch/cases/home.rxml

Clouds
http://vortex.plymouth.edu/clouds.html

Biology & Chemistry

Chemistry For Kids
http://www.chem4kids.com

Chemical Elements
http://www.chemicalelements.com/

Human Anatomy Online
http://www.innerbody.com/htm/body.html

Web of Species
http://www.wellesley.edu/Biology/Web/index.html

The Biology Project
http://www.biology.arizona.edu/default.html

Cells Alive!
http://www.cellsalive.com/