A local mushroom hunter found the bleeding woman around 4:50 p.m., lying by a dirt road near a forest.
The woman had suffered head injuries but was still conscious enough to say the word "bear," police said.
The mushroom hunter contacted the woman's son, who called an ambulance. The woman was rushed to a hospital, where she was confirmed dead.
Local authorities believe she was attacked by a bear.
Iwate Prefecture has one of the highest rates of bear attacks in the country.
There were 15 reports of bear attacks on humans in the four months following April 1, according to prefectural officials.
Comment: Bear attacks in Japan hit record high