I have a lot of slides taken by my grandmother mostly, from the 60s, 70s and 80s, some actually have the location and precise date recorded. I know its ok to post old photos, but these were not technically by me. I do own the material now as they have passed away.
Below, Feb 8, 1983, Binna Burra
I’ve read the ToS extensively and see absolutely no issue with this. I have a few relatives who do not use iNat and share their observations from time to time as I saw no object to doing so in any guidelines/rules.
First - it should be your own engagement with nature.
You were not, there, then.
It is allowed (just a few), but not encouraged.
Also copyright - so add a note to each obs with the backstory.
From the new Help articles
https://help.inaturalist.org/en/support/solutions/articles/151000169927-what-is-an-observation-
https://help.inaturalist.org/en/support/solutions/articles/151000169928-what-kind-of-photos-or-sounds-should-i-attach-to-observations-
Sadly, no:
Photos or sounds attached to observations should include evidence of the actual organism at the time of the observation, observed by the user who is uploading the observation. Media used in your iNaturalist observations should represent your own experiences, not just examples of something similar to what you saw. Please do not upload photos you found elsewhere, such as online or in a book, since they don’t represent your own experiences and are probably a violation of copyright law.
this is a different situation to
and what the OP is asking is not a breach of copyright. It is fine to do as they asked at a relatively low level
I wasn’t accusing them of that I was just including the whole para of the help faq and bolding all the various places we were told to only use our own photos.
I am confused by this. Are you saying we can now add photos from deceased relatives so long as we have inherited the photos and the locations are indicated, even if we were not there? This seems like a change of practice.
It would be a shame not to be able to share these photos somehow. Maybe we need an offshoot of iNat for historical photos. 
In all seriousness, is anyone familiar with a good way to preserve/share these? Maybe a museum would be interested? There’s always Flickr, I guess, but this situation feels more like a treasure hunt - who knows what actual data might be lurking in those photos! 
Here’s a thought: Could the OP create a separate iNaturalist account in the name of their late grandparents and upload appropriate images under that “first-hand” account? I don’t know if this opens up a can of worms for account management (for the OP or staff). Proliferation of such associate accounts might skew some stats and I could see it having unintended consequences.
@tiwane Your thoughts?
Imo it should be allowed, they dont have iNat, nor would make an account. And they have passed away. It would be a shame to let useful and interesting data go to waste just because their grandparents didnt live in a time where they had access to this platform. “Your own engagement with nature” you can make a case for it since OP engaged with nature through their family. That rule is mostly to prevent people from posting images they found on the internet or books. I think from a more ethical pov, you should make copyright be open (or how it is called, not sure of the tehnical terms) and also add the backstory. I dont think anyone would complain
As Diana said
A small handful of these does no harm in my opinion. Many hundreds or thousands would of course be a different question.
Where is this allowance noted @DianaStuder? I cannot find it.
edit to add: I do not doubt historical evidence may be useful though there would be no way of knowing if the location is accurate (or an “in the vicinity of”) and no way to ask the Observer (nor any other questions).
eg from https://forum.inaturalist.org/t/museum-specimens-antique-photos-and-inaturalist/31638 (bold text my emphasis)
Perhaps that ought to be incorporated into the FAQ then as it directly contradicts it. @tiwane
@tiwane’s comment was what I remembered from the times it has been asked before.
Here is a similar comment on that thread
Goodness, this could not be less clear.
I agree with this, and I think the various statements in the past by staff highlight that it is a grey area. e.g. iNat also “isn’t a place to post photos of humans” but most of the staff have a handful of these. : ) That there is a direct personal tie to the photos (through family) is personally why I think it’s fine - uploading museum specimens or “random” old photos would be different in my opinion.
If the grandparents took a photo of you standing in front of the tree - then it would be your experience (even if you don’t remember). I am going through old family photos like this, but I wouldn’t want to mess up my observation map with dots where I’ver never been.
Seems like this might be very valuable information since it addresses what was there in the past at a specific date. I have, with relatives’ permission, occasionally posted an observation for them, to gather information and contribute to the site. I always indicate it is not my photo and have received permission to so do. My dad had a wonderful shell collection from the South Pacific (WWII era), but I have no location or dates for the shells, so I cannot add even one or two. Your grandparents’ collection sounds wonderful. If it turns out you cannot post them here, there must be a place where they would be of value. I hope someone can recommend such a site or place. Good luck!
There is a very small collection of shells in my family collected by a relative in about 1880 in Chuuk, Micronesia. Alas, no specific locality or date.
