I haven’t read carefully, so apologies if this has been mentioned.
I would second UVM and UMass (though I see the student would like to be further afield)
Another one possibly not on the radar would be George Mason (Virginia public university, suburban DC). It’s definitely a big campus, but it’s not super sporty or Greek focused, but the campus is nice, definitely not rural and incredibly diverse. The GMU bio departmnet are partnered with the Smithsonian Conservation Research Institute, which is a bit away from campus and more rural, and they offer a robust undergraduate field focused biology education. Undergraduate Residential Semester-Away Programs - Smithsonian Mason School of Conservation
Including the option to do a full semester at the field site. Although GMU does have graduate programs, I get the sense that the faculty are still fairly focused on undergraduate teaching. It would be an easy admit, and they tend to give decent aid to out of state students.
The other one I might suggest would be St. Mary’s College of Maryland (public liberal arts college) - they definitely have a great biology department with lots of field focused faculty. I know less about their acceptance rate/aid
(I am a biologist/faculty and routinely advise students interested in pursuing biology, and I just finished the college application process with my younger kid - and so I have (or will soon) experience at both large state institutions and small liberal arts colleges as a parent, and would be happy to chat.