If you have never wanted to hit the road, maybe it’s that you haven’t wanted to escape something badly enough. Carll Tucker had a nice job, nice family, nice life in a nice, a very nice suburb of New York. But when his marriage expired, he got into an RV and took off for . . . where? The sites of American presidential and vice presidential graves? In “The Bear Went Over the Mountain: Finding America, Finding Myself’’ (Mary Ann Liebert, Inc., 281 pp., $19.95 in paperback), Tucker drives for nine months through 23 states, finds 65 headstones, and gleans quite a bit of information and insight out there west of the Hudson. Who knew that Charles Curtis, Hoover’s vice president, was a Kaw Indian? Or that Pierce’s vice president, William Rufus deVane King, and James Buchanan, later to be president, both lifelong bachelors, lived together for years in the capital? Or that King served only 45 days before he died of tuberculosis? Or that Grant was so poor he sold his remains to the highest bidder? And so Tucker meanders, unearthing the gruesome and the gossipy and the grand on his road trip, going from Wal-Marts to Mount Rushmore, Grand Ole Opry to yet another RV park, Timomium (Agnew) to Selma (King), Yorba Linda (Nixon) to Oyster Bay (TR), collecting among his notebook passengers men long forgotten but once interesting and powerful.