The Hutchinson County RootsWeb web site, www.rootsweb.ancestry.com/~txhutchi/
has a category for School Districts. Seems like this would be the perfect place online for the info in your school yearbooks. There is a link at that web site to their web master.
If you want to physically donate them, there is a Hutchinson County Genealogical Society, http://texashistory.unt.edu/explore/partners/HCGS/
. Looks like they're affiliated with their County Museum. Their phone # is 806-273-0130.
How generous of you to want to donate them where they will be seen and used by a larger audience! Reminds me that I need to do the same with my father's yearbooks.