The Northern Pacific Railway Historical Assn. has established an east end and west end
archive for donations of photographs and anything else related to railroading. The Great Northern Historical Society, Spokane, Portland and Seattle Ry Historical society and the Milwaukee Road Historical Association have also joined the NP archives. Go to the NPRHA.org website for links to the archives. Eastern Washington University Library in Cheney, WA is starting a railroad archive based on two collections of railroad photographs that have been recently donated from estates (in addition to what the university already had.) When you write your will, specify whatever archive or museum you want your stuff to go to, in addition, you can also specify how you want the stuff handled. There are other places, these are just a couple of active ones I've had successful dealings with. (P.S., keep your wills updated on a regular basis, one archive I know of lost a huge photo collection because a distant family member challenged the will as being too old to be valid, and found a crooked lawyer and judge to swing the estate to the very distant greedy relative. Could have been avoided had the will been updated or renewed every few years so it appeared current.)