Mom and Dad are off to Paris, but Grandma has a better trip in mind for Liz and Lenny. All three dress in clothes from the attic; then Grandma puts on her magic hat and takes the kids and the dog, Moose, back in time to 1843. There they join their ancestors traveling west in a covered wagon on the Oregon Trail. Stanley (A Time Apart, 1999, etc.) gives a humorous and historically accurate account, with tidbits about cooking on the trail, encounters with Native Americans, and hunting for berries and wild onions in the meadows near the Bear River. Even history buffs will find something new in this description; for example, the author describes removing the wheels from covered wagons, covering the wagon frames with buffalo hides rubbed with tallow and ashes, and floating the wagons across the river. The travelers and their dogs add their own quips and comments on the journey in conversation balloons. Berry (Market Day, 1996, etc.) provides appealing illustrations, rich in detail. The front endpapers show a map of the Oregon Trail in 1843 while the back endpapers show a map of the Oregon Trail today. An author's note explains that it stretches 2,170 miles and was traveled by over 400,000 settlers between 1840 and 1880. Young readers who have discovered The Magic School Bus will relish this adventure of “The Time-Traveling Twins,” and look forward to further adventures. (Nonfiction. 6-10)