Free Rangers, A Story of the Early Days Along the Mississippi by Joseph Altsheler

Historical novel from the Young Trailers series. According to Wikipedia: Joseph Alexander Altsheler (1862 - 1919), was an American author of popular juvenile historical fiction. Altsheler was born in Three Springs, Kentucky to Joseph and Louise Altsheler. In 1885, he took a job at the Louisville Courier-Journal as a reporter and later, an editor. He started working for the New York World in 1892, first as the papers Hawaiian correspondent and then as the editor of the Worlds tri-weekly magazine. Due to a lack of suitable stories, he began writing childrens stories for the magazine.