It was made in 1966 and starred Oliver Reed and Rita Tushingham.

It's set in North America (Alaska or Canada, I'm not sure) and is about a young woman with no speech sold to a brutal trapper. He buys her from her aunt and takes her away into the forest to live in a log cabin. They develop a love for each other, but he gets caught in an animal trap and she has to chop his leg off with an axe as he develops gangrene. Later she escapes, but on the point of marriage to a respectable man, she suddenly realises she loves her trapper, and goes back in a canoe to rejoin him.

The setting, wildlife and savagery of those times blends beautifully with the music. It's on Youtube, and you can just listen to the music at the very end if you don't want to view the whole film. It's extremely powerful stuff!