Military / sensitive locations property releases

[40nights]

Hello all,

I often hire photographers to shoot military facilities, water treatment plants, and other areas with security concerns.
My company hasn't yet developed a standard property release form or process to help clear security concerns.
I'm researching to see if a site/property release form can or should be used. I also need to know if a letter or contract before the photo shoot is the best/most efficient approach. Or is it better to simply clear the images with the facility security folks after the shoot is over?
Does anyone have any experience with these kinds of issues or know of any resources that might be helpful?
We have contacted Public Affairs at a couple of bases and they indicated that such shoots would be subject to review on a per-case basis. But there must be some sort of basic process we can initiate in advance.
Thanks for any input you can offer.

Nathan

[40nights]

I should also clarify -- My company does contracted work on the bases and we'd like to use photos of the work to use in our marketing materials. Thus, we have to approve the shoots through the base officials first.