Mr. Simpson first began visiting Maine in the 1930s, and thereafter spent summer vacations there for the next seven decades.
He acquired a tremendous knowledge of the geological features and birds and animals that inhabited the Maine woods.
About 30 years ago, he and his wife purchased Chairback Mountain Camps near Greenville, Maine, where they enjoyed hiking and canoeing with family and friends.
"Howard was a natural woodsman from the city," said Ernest F. Imhoff, a retired Sun editor who often visited the Simpsons' camp. He recalled Mr. Simpson explaining to his fellow hikers what flowers they were looking at or what song was coming from some distant, unseen bird.
"It's a good thing a bear didn't show up," Mr. Imhoff recalled, with a laugh. "On the summit, Howard was quiet and resting when beautiful cloud forms rolled by. He could have explained them, too."
Mr. Simpson had been a member of the governors of the Bond Club of Baltimore. He had served on the board of Boys' Latin School and in 2004 received the school's Distinguished Alumnus Award.
He also had served as chairman of the Williams College Capital Fund for the Baltimore area.
Mr. Simpson was a member of the Maryland Club, Center Club and L'Hirondelle Club.
At his request, no services will be held, and interment in Elizabeth, N.J., is private.
In addition to his wife, Mr. Simpson is survived by two sons, John S. Simpson of Hunt Valley and David G. Simpson of New York City; two daughters, Leah Kalish of Los Angeles and Fay Simpson of New York City; six grandchildren; and four great-grandchildren. An earlier marriage to Keats Van Alstyne ended in divorce.