Mack "Jack" Slye Crippen, 77, the colorful owner of Great Falls' "Stump Dump," where Russians and the CIA stashed their trash and which he later turned into an exotic animal farm, died Feb. 9 of pneumonia at Reston Hospital Center.

Mr. Crippen could be described as a developer, but that would miss his exuberant willingness to charge into projects that, in an urbanizing Northern Virginia, struck many as unusual.

Conventionally, the Fairfax County native built a 120-house subdivision called Lockmeade in Great Falls and the 281-acre Lake Fairfax Park, which he sold to the county in 1966 for $1.7 million. He founded and was a director of Town and Country Bank. Through his companies, he also owned the Alexandria trash transfer station, the Potomac landfill in Dumfries and the Reston farmers market, and he served for five years on the Fairfax County animal control board.

At the time of his death, he was working on an ambitious and controversial effort to "mine" the Potomac landfill of valuable construction debris, then redevelop the land.

But he was also known in his younger years for flying his Bell Jet Ranger helicopter to garden parties and landing at the courthouse to pay a bill or at the old Lord & Taylor store in Falls Church so his family could shop.

"By golly, as long as you are not hurting anybody, anything is okay in my mind," he told The Washington Post in 1995.

That "anything" included importing exotic hoofed species to populate his private animal park, where he threw safari parties for his friends. The park was built on what had been the Stump Dump, a 65-acre landfill on Utterback Store Road in Great Falls. The dump began by accident in 1971.

"I was out there milking cows and a fellow came from Reston with a couple of tree stumps," Mr. Crippen said. "I told him to put them back there in the gully. He came back the next day with another three loads and a fellow following him. The fellow offered me $10 per load, and before the sun went down, I had $100 cash in my pocket. The bells went off and I was in the landfill business."

Before the county got a court order to stop him from accepting junk without a license, Mr. Crippen had a significant pile of refuse on his property, the second-highest spot in Fairfax, with views of Maryland and the District.

By 1979, the then-properly licensed landfill was also home to some of the remains of the world spy game. The CIA, based just a few miles away, dumped trash there but first shredded its paper, chemically removed the ink, ground it and compacted it. Foreign embassies routinely sent trucks full of trash.

The Russians arrived every few months, paying the dump fee in cash or bottles of vodka. A landfill employee would then call the FBI, whose agents would soon arrive to paw through the discards, usually restaurant receipts and parking tickets but once a stripped-down, brand-new Russian car.

Mr. Crippen, a blunt-spoken descendant of a Confederate Army general, Joseph Wheeler, was born on a dairy farm in western Fairfax. He graduated from Herndon High School and called himself a college dropout from Virginia Tech. He spent his life around animals, milking cows, auctioning cattle, hunting foxes and running steeplechases. He was a member of the Fairfax Hunt and a founder of the Virginia Gold Cup. He won the Martini and Rossi steeplechase trophy in 1966.

His next-door neighbor, his wife said, was animal activist Arthur Godfrey, who started Mr. Crippen's exotic collection by giving him a pet llama.

Mr. Crippen started the Reston "Pet-a-Pet" Zoo, commonly known as the Reston Animal Park, in the late 1970s, although he sold it within a few years.

He was not without controversy. Neighbors of the Reston park and the Great Falls landfill complained about odors, noise, dust and safety violations. He had several run-ins with local and state authorities. Fire officials detected high levels of odorless but explosive methane rising from the rotting trash at the Stump Dump, and Fairfax's animal warden hauled him into court because he lacked required permits to own and breed exotic animals.

When the state and local governments ordered him to close his Great Falls landfill in 1988, he decided to convert the lot into his own Wild Kingdom, which his wife dubbed Lockmoor Park. It was home to dozens of species, including zebras, gazelles, antelopes, giraffes, kangaroos, prairie dogs, buffalos, llamas, camels, ostriches and aoudads, which are a spiral-horned African sheep.

The county prohibited him from importing lions, bears, leopards or other carnivores, and that seemed like a good thing because Mr. Crippen had some trouble with an ornery bull elk.

"He had a nice big rack and that little bugger went to punching holes in zebras and picking my goats up and throwing them around," Mr. Crippen said. "I [tranquilized] him, put him on the truck and sold him." The property was private and closed to the public except for visits by schoolchildren.

But in May 1995, someone crept in and shot to death one animal in his herd of prized Watusi cattle. When the carcass was found 12 days later, its head was missing. The loss of the pregnant cow, named Love Potion and valued at $5,000, broke his heart.

"I just loved her. She was a beautiful animal," he said.

His marriage to Irene Bettius ended in divorce in 1978, but not before he obtained her permission to sell an elephant from their jointly owned Reston animal park. The judge said that in his experience it was a first for a divorce proceeding.

Survivors include his wife of 25 years, Sandra L. Crippen of Great Falls; two children from his first marriage, Mack "Lock" Slye Crippen III of Reston and Martena Wiegand of Bethesda; and six grandchildren.