Tucson environmental activist Rich Genser was a catalyst in Pima County's effort to protect Sonoran Desert land.

He was also a real estate investor and builder who saw no contradiction between his livelihood and his activism.

Genser, who moved from Tucson to Vermont two years ago, died Wednesday night at University Medical Center here. He had suffered a heart attack and a series of strokes while on business in Tucson in connection with the Tucson Gem, Mineral & Fossil Showcase. He was 63.

"He firmly believed that if we don't do something radical to protect everything here, there will be nothing left to protect. He was a fanatic about it, to the point that he would become enraged over things that went on," recalled his widow, Claire, who now lives in Manchester Center, south of Burlington, Vt.

Born in Newark, N.J., he moved to Tucson in 1987. In Arizona, he was a local and state Sierra Club chairman and was a founder and board chairman of the Coalition for Sonoran Desert Protection. He was a fixture at public meetings on growth issues, offering often-piercing testimony in favor of preservation and regulation of growth on environmentally sensitive lands.

In New Jersey, he was a real estate speculator and car dealer. In Tucson, he first bought and managed apartments and office buildings. In the late 1990s, he sold his interests in them to a real estate investment trust and with his son-in-law started a company called Blue Properties that bought smaller rental properties, built and redid casitas and renovated Tucson homes.

He also built a house in the luxury Stone Canyon development in the 7,000-acre Rancho Vistoso in Oro Valley, and several custom homes in the Gallery development inside the 5,600-acre Dove Mountain project in Marana. Genser tried to make sure that the homes were built in harmony with the land and wildlife, his wife recalled.

"He wanted to be a developer with a conscience," she said. "Rich's take was, 'I fought 'em and lost the battle; I'll just make sure that when we build the houses that they're environmentally correct and beautiful.' "

He was a lifelong outdoorsman who hiked, kayaked, skied and rode mountain bikes, among other pastimes. He was also an avid golfer who played only on courses using reclaimed water, Claire said.

Carolyn Campbell, the desert protection coalition's director, recalled that a decade ago, Genser led the push among activists for what became the county's Sonoran Desert Conservation Plan. He and others wanted to make sure that environmentalists had more influence in crafting the plan than they had with similar plans in other cities.

Bill Arnold, a Realtor and property rights activist, recalled that his first encounter with Genser was hostile but that over time he grew to appreciate his passionate views.

"He was the kind of opponent I enjoyed working with. He was honorable, told you where he came from, didn't pull any punches and negotiated in good faith," Arnold said.

In addition to his wife, Genser is survived by his father, Lester, of Del Ray, Fla.; a son, Jordan, of Tucson; a sister, Susan Bulger, of West Orange, N.J.; a brother, Jon, of West Orange; two stepdaughters, four grandchildren, three nieces and a nephew.

A memorial service was held Saturday at Skyline Country Club. He requested that memorial donations be made to the Sierra Club of Tucson and Angel Charity for Tucson.

A public forum held Saturday in Green Valley for conservation groups on the proposed Rosemont Ranch mine was dedicated in his honor.