Well, crap. I was about to take another trip down there soon.
If there are any all-purpose consignment shops in your area, they may take them. These stores vary widely in what they will take, and how the funds are disbursed. Some will not mail checks, so that may be a problem if you’re leaving the area.
Yeah, I looked them up after you mentioned them and found out about the fire. 
If the kind of stuff you want to see is used textbooks from the 1980s then you have very unusual tastes.
In some fields older textbooks aren’t much different from newer ones. So someone wanting to study, e.g., Differential Equations on their own might be happy to get a 40 year old book for a buck. But if they have a choice between a 3 year old book and an older one, they’re going to take the newer one. Old textbooks are almost always unwanted by all organizations.
My field is Computer Science. Most books become worthless within a few years. What I did a couple months ago in a round of clearing out was cut off the cover of hardbacks (including the cloth/plastic spine) and add them to the recycling bin. (They otherwise don’t take hardbacks but they do take paperbacks.)
Half Price Books where I live. Since I used to sell books as my main business, I probably would have already tried eBay or Amazon. So unwanted books (in my definition) would have very little if any value, but a place like Half Price Books would take them all and would buy some (and happily dispose of the rest).
As others have said, many libraries have book sales. At our library donated books are sorted. some go for the sale, some to the used book store in the library itself, and some are kept for a recyclying business that comes on a regular basis.
The building I work in also houses the main branch of the County Public library. They have donated book sales about 3 times a year. It’s a VERY popular event.
Anyway, I just cleaned out our DVD collection (yes, some of us still watch DVDs) and donated a dozen or so that we will never watch again to the library.
Just a heads up. The library will/might take music and DVD’s.
Some libraries even take VHS tapes and other obsolete formats. You do need to call first; the one I volunteer at takes VHS and cassette tapes only for children’s and seasonal items, but the neighboring town will take anything that’s in salable condition.
You never know what people will want. I just found out that my brother, who works in IT, likes to read old computer books for fun (we’re talking 1970s or older) but then again, I like to read old medical books for fun, as does his oldest daughter, so there must be something genetic there. 