John V.N. Klein, an extraordinary Suffolk County executive, has died at 90.

Mr. Klein held the top post in Suffolk County government between 1972 and 1979.

A huge achievement of his, which had national impact, was the Suffolk County Farm-land Preservation Program, now emulated across the United States. And it has kept Suffolk still among the top farming counties in New York State.

The program’s inspiration was a ride in a helicopter heading east from western Suffolk County. As he looked down, Mr. Klein, who grew up in a bucolic Fort Salonga in the Town of Smithtown, viewed western Suffolk, so much of it covered in subdivisions and shopping centers, crisscrossed with highways, a stark contrast from when he was young.

Then, eastern Suffolk appeared below, green and verdant, with many farms, made more unusual by their placement juxtaposed with water — the Atlantic, Long Island Sound and numerous bays.

He began thinking: How could this be saved?

The solution was what was then a first-in-the-nation concept: purchase of development rights. Suffolk County would pay the owners of the farms the difference between what the farms were worth in agriculture and what they could be sold for as sites for subdivisions. In return, the owners would sign binding legal papers keeping the land remaining in agriculture in perpetuity.

Since the program began in 1974, wineries have been added to Suffolk’s agricultural mix. And farming continues to provide a base for tourism in Suffolk — and fresh food close by.

Mr. Klein stood strong against the scheme to turn Suffolk into a “nuclear park, ”in the parlance then of nuclear power promoters. They planned seven to 11 nuclear power plants here. Under Mr. Klein, Suffolk County government declared its opposition to nuclear power in Suffolk and waged a battle that would continue for many years, and ultimately was won. 

Mr. Klein was the leading critic of the plan of the U.S. Army Corps of Engineers to construct groins — rock jetties — on the Westhampton Beach oceanfront. It was folly, said John V. N. (for Van Nostrand, his descendants were early Dutch and German settlers on Long Island).

It would be, he said, “hand-wrestling with God.” And, it would be “robbing Peter to pay Paul” with the groins catching sand moving in the ocean’s westward “littoral drift” along the south shore, but robbing it from homes farther down the coast.

He lost that fight. But was proven correct. The Corps is now moving ahead with its Fire Island Inlet to Montauk Point project, which the Westhampton construction decades ago was a part, but without any groins for the reasons Mr. Klein cited.

He led the county in challenging the plan of the oil industry to drill off our coast, pointing to the routine oil spillage from offshore operations and the impacts of spills on Suffolk.

A Republican, he began in government as town attorney of Smithtown, then was elected town supervisor. He was the last chairman of the centuries-old Suffolk County Board of Supervisors, replaced by the Suffolk County Legislature in 1970.

So committed to Suffolk, he gave up being a supervisor to run to be a legislator on the new panel and became its first presiding officer.

He established a close relationship with Suffolk’s first county executive, Democrat H. Lee Dennison, elected to the new position in 1960. When he was board chairman and then presiding officer of the legislature, Mr. Klein and Mr. Dennison would sit with the press after meetings and discuss what happened. Both were open and frank. Their warmth for each other was palpable. Mr. Klein would succeed Mr. Dennison as Suffolk’s second county executive.

It looked for years like Mr. Klein was headed for statewide or national office. “His horizons are unlimited,” said Suffolk GOP Chairman Edwin M. (Buzz) Schwenk in the 1970s of the articulate, highly-intelligent Mr. Klein. Said then New York Attorney General Louis Lefkowitz: “I think he is one of the most outstanding men I have ever seen in public life.”

Then in 1979 the controversy over the county’s $1 billion Southwest Sewer District scandal included a challenge in a GOP primary to Mr. Klein’s renomination, and he lost.

He went on to decades of prominence as an attorney on Long Island. He and his wife, Audrey — they lived in St. James in Smithtown — moved to Virginia, where he had received undergraduate and law degrees from the University of Virginia in Charlottesville.

Audrey predeceased him. They were married for 62 years. Mr. Klein died in Virginia on Dec. 22.