William S. Tiernan, 67

William Scott Tiernan of Laramie, Wyo., who spent childhood summers in East Hampton, died on July 27 in a fire at his house there. He was 67.

Known as Scott, or Grand Dude to his grandchildren and Wild Bill when on his Wyoming ranch, he was born on May 18, 1951, in West Orange, N.J., the second of four children of the former Lynda Scheerer of East Hampton and Gulf Stream, Fla., who survives, and John William Tiernan, who died before him.

Mr. Tiernan grew up in Delray Beach, Fla., Cape Cod, and East Hampton. He graduated from Avon Old Farms School in Avon, Conn., where he lettered in football, wrestling, and lacrosse. After graduating, he served on the school’s board and donated a wrestling room in honor of his father.

His family said that he “packed a lot of lives into one” and that he may have attended college “for a minute” but had too much to do and see to stay long enough to get a degree. He traveled around the world and had many adventures before moving to Gulf Stream, down the road from where he had grown up, and becoming a partner in the real estate brokerage firm Allmon and Tiernan (which would later become Allmon, Tiernan, and Ely before being sold to Corcoran in 2005).

He also served for a time on the board of the family’s company, the resortwear and sportswear retailer Mark, Fore and Strike, which was started in 1951 and bought from its founders by Mr. Tiernan’s father. It was sold in 2003.

After Mr. Tiernan retired, he bought a piece of property outside Laramie, where he built a ranch and made huge metal sculptures, which, his family said, delighted his grandchildren.

Living life to the fullest was always foremost in his mind, his family said, as were motorcycling, snowboarding, sailing, and surfing. “The man was fearless,” the family said. “He was a surfer dude, a family man, a businessman, a cowboy, and an incredible artist.”

In summers, even as an adult, he would visit his mother, now Lynda Scheerer Stokes, at her East Hampton house. In addition to her, Mr. Tiernan is survived by his brother, Michael Whitaker Tiernan, and his sister Ann Purcell Tiernan, both of Delray Beach, and his other sister, Martha Tiernan Ely of Gulf Stream; his daughter, Cary Tiernan Butterfield of Bermuda; his three sons, Scott Durand Tiernan of Newport Beach, Calif., Parker Knight Tiernan of Delray Beach, and John Sears Tiernan of Great Falls, Mont., as well as three grandchildren. Mr. Tiernan’s two marriages — the first to Carolyn Riley, the second to Kim Allmon Tiernan of Guana Cay, Bahamas, the mother of his four children — ended in divorce.

In addition to his immediate family, he is survived by scores of friends “who will remember fondly his bright blue eyes, surfer dude hair, and thirst for adventure,” his family said. “As he moves on to this last, most epic adventure,” they said, they all wish him “fair skies and big waves.”

Mr. Tiernan’s children spread his ashes at his ranch, as he had requested. They are planning a celebration of Mr. Tiernan’s life for a future date.