Murder on the Appalachian Trail. The detective is John Thatcher, a senior vice-president of the Sloan Guarantee Bank in NY. He's a guy with a nose for money and villainy.
Emma Lathem is one of the major American detective storywriters in the middle to later 20th century. Newsweek said about her, "A masterful plotter, an elegant stylist, a comic genus, and an old fashioned purist who never sacrifices logic for surprise effect." John Putnam Thatcher has been ranked "alongside Nero Wolfe, Philip Marlowe, and Sam Spade at the summit of American detective heroes." (St. Louis Post-Dispatch) Always a fun read.