Douglas V. Weed, wrote a great book titled “They Never Surrendered” about Southern AZ Apache who still raided and caused havoc along the U.S.-Mexican up until the mid-1930s.
He argues that the Indian Wars did not technically end with the surrender of Geronimo in 1886 and noted that many residual Apaches retreated shortly thereafter into the Sierra Madre Mountains
I’ve read those accounts too.