This from a small Indiana library website: At no other place in the world can you visit one place with such a vast amount of knowledge and plethorically resources. Please come visit us.

"Plethorically resources?" What do you suppose they meant?

Well, Dictionary.com gives two definitions for the adjective plethoric:
1. overfull; turgid; inflated: a plethoric, pompous speech.
2. of, pertaining to, or characterized by plethora.

I'll take a guess that they meant the second, but used the adverbial form, plethorically instead.

Arnie, I suspect they didn't have a clue as to what they were saying! Here's the link to the site - it's at the bottom center: http://www.bell.lib.in.us/

Agreed. I took a quick look round the site and noticed several instances of poor writing or phrasing. It might have been an idea to show the text to the library staff before publishing it ...