Cardinal Numbers

Amazon.com sales rank of Starr’s Guide to the John Muir Trail and the High Sierra Region: 83,755

Gear items required for Stanford’s Introduction to Wilderness Skills: 34

Percentage of U.S. college graduates who are “very afraid” of being alone in a forest: 7

Percentage who are very afraid of looking down from a great height: 23

Height, in feet, of Hoover Tower: 285

Height, in feet, of Herbert Hoover: 5.92

Sources: Amazon.com, Stanford University, Harris Poll, National Safety Council, Herbert Hoover Presidential Library Association