A definitive guide and then some to what seems to be every mile of the more than 5,000 traveled by Blocksma (Naming Nature, not reviewed) along the US side of the Great Lakes. The author's comprehensive narration of her three-month solo expedition is not in the least restricted to one unifying theme. Camping enthusiasts will discover which state parks have open sites and which are wooded (mosquitoes are ubiquitous at all of them); geology buffs can read about sand dunes, rip currents, glaciers, and the five types of wetlands; the reader learns that the lakes saw some 50 shipwrecks a day in the late 19th century and that Sandusky, Ohio, once had the largest roller coaster in the Midwest. The indefatigably curious Blocksma tours a sewage treatment plant on Lake Erie and a nuclear power facility on Lake Michigan; is warned away by guards at the gate of an exclusive resort in Harbor Springs, Mich.; visits the birthplace of the dune buggy; and parasails over Grand Traverse Bay. At a lunch counter near Green Bay, Wis., she discovers that more than 12,000 people are on the Packers season-ticket waiting list. At times, Blocksma's encyclopedic prose threatens to overwhelm the casual reader. She is fond of nautical measurements and a compulsive maker of lists, noting everything from fish species to park fees. Yet there is something agreeable about her wide-eyed excitement over this abundance of minutiae and arcane detail; her attention to statistics and description at times echoes John McPhee. Even more praiseworthy is her tenacity, as she camps alone and interviews a dizzying number of park rangers, fishermen, sailors, historians, nuclear-plant workers, hoteliers, and seemingly anyone else within reach--though some of the conversations are amazingly mundane. Blocksma contributes mightily to our understanding of a vital section of the continent.