I read this book in the 90s and gave it away but now want to reread it. The main character is a male fur covered yeti-like creature and part of a species that have 3 stages of life and the book is split into these 3 sections (with the last being titled "Monolith"). The entire book takes place on a planet that is half super heated and volcanic, half frozen wasteland and all life lives where these two sections meet. Humans are the "bad guys" and basically have come to the planet and hunted the protagonist's species to extinction. As the assumed last of his species he lives out his juvenile life away from humans in the colder/snowy/frozen part of the planet. He becomes aware of a female of his species that has been captured by humans and is going to be taken off world. He then rescues her and they go off to mature and have offspring. The offspring and his mate are hunted and killed or abducted and taken off world by humans. As the actual last of his kind he passes into the senescence/old age/Monolith stage of his species life cycle where he becomes huge/tall and wanders the wintery wastes alone. While doing this he becomes aware of an outcast group of "Rememberers" (another species that are small with big heads and able to remember and recite lots of information, a bit like the Mentats of Frank Herbert's Dune in their role as biological computers). The book ends with the protagonist taking these "Rememberers" up into the frozen wastes and teaching them how to live and all about his species and their culture with the idea that "my species might not survive biologically but their culture will live on in this new group".
I hope that's enough to go on as I've been searching for this book for years without any luck.