By Kate Messner
A golden retriever gets pulled back to 1850 and helps a pioneer family survive the Oregon Trail.
Ranger is a golden retriever who trained as a search-and-rescue dog but flunked the test because he can't resist a squirrel. One day he digs an old first-aid kit out of the yard, and it pulls him back to 1850, onto the Oregon Trail. He joins the Abbott family's wagon and their son Sam, and then things start going wrong: a buffalo stampede, a sickness that spreads through the wagon train, a river crossing that nearly drowns someone. Each time, Ranger is the one who gets them through.
The whole thing is told from Ranger's point of view, so a child who loves animals is in before the time travel even starts. Chapters are short, the black-and-white pictures carry a lot of the danger, and the history goes down easy because you're following a dog, not a lesson. And every book in the series drops Ranger into a different real moment in history, so a child who finishes this one has ten more lined up.