Now you are ready to look at field trips themselves. Choose which way you would like to view the site -- with frames or without. I wouldn't suggest choosing frames unless you can open up your browser window really wide.
If you are an older student you should have no problem understanding the "Effects of Nitrogen on Biodiversity at Niwot Ridge" field trip as well as the biodiversity (plants and animals) field trips. You younger students might find the Nitrogen trip a bit out of your range, but feel free to check it out if you would like.
Enjoy your tour!