When Grizzlies Walked Upright

When I read this story, I didn't really understand how a Sky Spirit came down from the sky and created earth. He created a mountain with trees, rivers with fish and otters. Also when the sky spirit took his family down from the sky to live on the mountain the daughter "flew away" and down the mountain because of the wind spirit. And when the daughter flew away, she met a grizzle bear that she fell inlove with and made a family with. People and bears making a family is not possilbe. This story confused me also at the end when the grizzlie sets out to find his child he somehow got cursed. Now all grizzlie bears from that moment on would walk on all four legs and never speak again.