"The Sugar Creek Gang Goes Camping" by Paul Hutchens (Sugar Creek Gang, Book 4)

Bill Collins and Little Jim survive a wild ride on the flooded Sugar Creek thanks to the acrobatic efforts of their friend 'Circus.' When summer arrives, the gang heads to Pass Lake, Minnesota, for a camping trip. There they discover a railroad coach in the middle of a forest without any railroad tracks, and an honest-to-goodness Indian with beads and a war bonnet. Follow the adventures of the Sugar Creek Gang as they experience the meaning of being saved, both physically and spiritually.