What happens in part 1 of "The Woman Who Rode Away"?

In the first part of the short story, the reader learns about an unnamed woman—originally from Berkely California—who is tired of her life on a ranch. She thought her marriage to a rich businessman would be an adventure, but instead she is forced to stay at home while her husband goes on business trips. He occasionally takes her out, but he tells her she can't go out by herself because it is dangerous.
One day, one of her husband's visitors piques her interest by discussing what exists behind some hills they can see from a distance from the house. Her husband tells him that "there's plenty of game, if you want to shoot. And Indians." He thinks that some of the Indians are friendly, but "some of them are quite wild. They kill a missionary at sight. And where a missionary can't get, nobody can."
While her husband is away, the woman shocks her servants and children by taking a horse and riding out into the wilderness towards the hills. Her goal is to get to "the Chilchuis, living in a high valley to the south, who were the sacred tribe of all the Indians."
After travelling a few days, she meets some Indians, who—despite being shocked that she is by herself and that (as she tells them) she voluntarily left her family—agree to take her to the Chilchuis. At the end of the first part, she says she was "aware that she had died."