Timothy Means, a conservationist who was on the leading edge of ecotourism in the Gulf of California and helped win permanent protection for hundreds of islands off the Baja Peninsula in Mexico, died Aug. 13 at a hospital in San Diego. He was 75.

His son, Carlos, said the cause was complications of diabetes.

For most of his life, Means was immersed in the natural world. He spent decades working to protect the fragile desert ecosystem of Baja and the Gulf of California, also known as the Sea of Cortez, a body of water so teeming with life that Jacques Cousteau called it “the world’s aquarium.”

Inspired by environmentally conscious tourism on the Galápagos Islands, Means set up Baja Expeditions in 1974. It was one of the first major low-impact nature tourism companies in Mexico.

The remote southern Baja Peninsula is a region of rough, pristine beauty, with abundant flora, fauna and marine life. Means derived enormous pleasure from showing it off to groups of 15 to 20 tourists at a time, many of whom became donors to his nonprofit projects to help keep the area under federal protection.

The region also proved attractive to developers, including one who in the early 1990s wanted to build a resort casino on the rocky Espiritu Santo Island in the Gulf of California.

Means led the way in stopping the project. He organized a coalition of philanthropists, business owners and local fishermen in opposition to it and raised money on both sides of the United States-Mexico border. He personally purchased the land in the middle of the proposed casino site, and the coalition subsequently bought the entire island for more than $3 million. The island was given as a gift to the Mexican government, which then granted it permanent protection.

Though he was a man of few words, Means had a way of conveying the importance of his projects and recruiting people to his causes. He did this by strategically inviting a range of visitors, including scientists, filmmakers and potential donors, on his expeditions, where they would connect with one another and the natural world.

For the Isla Espiritu Santo project, the big donors included the Nature Conservancy, the World Wildlife Fund and the Walton Family Foundation, as well as individuals like Manuel Arango, a Mexican businessman.

Mexican environmentalists later used the coalition’s purchase of Espiritu Santo and the government’s protection of it as the inspiration for a wider preservation of coastal sites in the gulf, said Anne McEnany, president of the International Community Foundation, a nonprofit organization that supports charitable giving overseas. In 2005, UNESCO designated 244 islands, islets and coastal areas in the Gulf of California, including Espiritu Santo, a World Heritage Site — an area of ecological significance legally protected by international treaties.

In 2007, Mexico named the Espiritu Santo Island Archipelago a national park.

Timothy Irwin Means was born March 18, 1944, in Beaver Falls, Pennsylvania, to Melvin Wayne and Flora Agnes (Heineman) Means. His father was an electrician, his mother a homemaker.

When Timothy was a child, he had a heart condition, and the family moved to Phoenix in hopes that the dry climate would help. Over time, the problem corrected itself. His father worked in Phoenix as a lineman for the local phone company and later at the Hoover Dam.

Timothy studied geology at Phoenix College but never graduated. He worked as a raft guide on the rapids of the Colorado River in the Grand Canyon. A brief marriage to Judy Fredrickson in the mid-1960s ended in divorce.

He later met Nora White, a young woman from Santa Barbara, California, who had sailed to La Paz in Baja. She soon joined him in running the tourist expeditions.

In 1980, they held a somewhat impromptu (and unofficial) wedding ceremony on a sand dune during one of their ecotourism trips; the marriage was legalized in 1982. They separated in 1996 and were divorced in 2012.

In addition to his son, Means is survived by his mother; his daughter, Magdalena Means; his sister, Marilyn Means; his brothers, Wayne and Dean; and a granddaughter.

Means came to love his adopted country so much that in 1993 he became a Mexican citizen.

White, his former wife, said that she was initially skeptical of ecotourism. She felt that bringing tourists to a fragile ecosystem was self-defeating and not environmentally sustainable. But, she said, she came to change her view: The groups were small; they traveled with minimal impact on the land and water; and, most important, their eyes were opened to how much the area needed protection, especially from rapacious developers.

“Tim raised awareness of the environment and used the business as a mechanism to find donors for conservation,” she said. “He got people to see what was important and to donate to the cause.”

Along the way, Means began devoting himself more fully to conservation. In 1990, he helped found the Niparajá Natural History Society (Sociedad de Historia Natural Niparajá), a nonprofit association to preserve the coastal wild lands of the Baja Peninsula and promote sustainable fishing.

He also helped buy an old ranch on the coast of the Sierra de la Giganta mountain range on Baja as a reserve for bighorn sheep and other species.

He supported research and educational efforts to protect marine life and sustain healthy ecosystems throughout the region, and he led numerous expeditions with students and others to draw attention to the problems caused by overfishing and overdevelopment.

People who took part in Means’ trips fondly recalled that whenever he greeted or bade farewell to them, he would belt out the signature ranchero call: “Woooop!”