Can a county donate surplus property to a neighboring county? If so under what authority.

Not that I can see. The county may sell surplus property to another county without using a competitive bidding or auction process. See Loc. Gov't Code sec. 263.152(a)(1). The only authorization for donation is in subsection (a)(4), which allows donation of surplus property to a civic or charitable organization within the county if sale of the property--essentially--isn't worthwhile, the donation serves a public purpose and the county will receive some value, such as being relieved of disposal costs. Otherwise, the whole "gift" bugaboo of art. 3, section 52(a) of the Constitution arises.

Thanks for the reply. That was my conclusion as well, just checking that I was not missing something.

Is there a way to transfer to property pursuant to some sort of intergovernmental agreement? Any service or value they can provide to you in return?