This was a hardcover chapter book I read in the ’60s. Don’t know when it was published, but it felt like contemporary writing, though the story was set in the early 20th century. No illustrations. A very young man lives with his mother in a small town- the nearest city is Spokane, I think. Possibly his older brother is missing. He goes to the ice cream parlor and has a pineapple ice cream soda. There is some sort of quest, some railroad tracks. He fights a cougar or puma, and is wounded, and emerges scarred but triumphant. He gets the girl.