PRI's Earth@Home at https://earthathome.org/
"Discover the geologic history of the northeastern United States! Explore
our free, open-access "Digital Encyclopedia of Earth Science" textbook.
Investigate our interactive Virtual Fieldwork Experience programs and
discover why a place looks the way it does. We offer a range of tools to
help you experience Earth science online." Don Haas (firstname.lastname@example.org)