Residents in three fast-growing Boise neighborhoods say that evacuation efforts could trap them there if the wind blows the wrong way or the main road becomes blocked.

Hundreds of residents of three subdivisions in Southeast Boise near Micron have only one escape route: Columbia Road. Developers have plans for more homes.

In Brooklyn’s Prospect Park on Sunday, onlookers gawked at a charred hilltop, where newly fallen leaves had already obscured ...