fiction, post or super-human gorilla society discovered in mountains of africa

Seeking a fiction book, secret post or super-human gorilla society discovered in mountains of Africa. Its society, culture, and technology is developing toward bodiless astral projection. I read it in the 1970's, but don't know the publication date.

Michael Crichton's Congo came out in 1980 but I don't think the gorilla hybrids in that were as socially developed.

This sounds like the 1973 novel by Dale Bick Carlson The Human Apes.

https://www.goodreads.com/book/show/6100354-the-human-apes

https://openlibrary.org/books/OL5304302M/The_human_apes

The latter shows an alternate cover (which is the one I remember seeing when I read it)

Whether or not The Human Apes is what the original poster was thinking of, it's a book that *I* couldn't remember; thank you for that!

In this one, the society in question were aiming at evolving along the lines that the aliens in Arthur C. Clarke's 2001: a space odyssey eventually did, or at least that's how I think of it...

@DissassemblyOfReason. Agreed. I think that is a good way to describe the goal of what they were trying to achieve.