For couples searching for an idyllic setting for their wedding, Sunset Ranch is tempting.

The 27.4-acre spread near the peak of Pupukea Road on the North Shore of Oahu is advertised as an exclusive, private country estate with breathtaking ocean and island views. Couples have their choice of a handful of wedding and reception venues that can accommodate hundreds of guests, from Charlie’s Pond to Fern’s Garden to Sunset Stables.

Brides and grooms can relax in renovated guest suites. Guests can celebrate in lavishly decorated tents, tropical gardens or a grand, rustic barn complete with chandeliers.

In 2008 and 2009, when preservationists applied for $2.4 million in federal, state and city money to protect Sunset Ranch from being carved up into gentleman’s farms, the only commercial use planned for the property was a horse stable for boarding and riding lessons.

Sunset Ranch’s agricultural zoning and conditional-use permits for agribusiness and outdoor recreation do not allow the commercial weddings and receptions, engagement photo shoots and other events that have routinely been held over the past few years, according to the city.

The city warned Sunset Ranch in January that continuing to host such events is a violation of city land-use law, and while the ranch’s owner, Greg Pietsch, applied in May for modified permits that would allow for commercial weddings and other events, the events apparently continue while the city reviews the application.

"We continue to work with the Department of Planning and Permitting in good faith. And we believe we have a strong legal and factual basis for all of our uses at Sunset Ranch," said Pietsch, president of real estate and finance firm Pietsch Properties LLC.

Pietsch, born and raised in Hawaii, divides his time between Sunset Ranch and Newport Beach, Calif.

"We hope to find a resolution on this matter in the very near future."

The history of Sunset Ranch is a microcosm of the challenges of preserving agriculture and open space on Oahu. It demonstrates the financial pressure many landowners feel to develop, the difficulty in making ranching and farming economically sustainable, the limitation of a conservation easement and the struggle of government enforcement.

The Pietsch family, which has been a prominent player in Hawaii real estate and development, first acquired Sunset Ranch in 1960. The ranch has mostly stayed in the family’s hands for the past five decades, save for the few years it was held by a local chapter of the Seventh-day Adventist Church. It was acquired by Pietsch Properties in 2005.

Pietsch, whose background is in investment banking and real estate development, said his intention was to subdivide the land into 12 lots in a gated farm community and keep a few acres for his family.

North Shore preservationists who opposed a subdivision suggested a conservation easement as an alternative. Sunset Ranch sits near historic Waimea Valley, the Pupukea-Paumalu Forest Reserve, the Boy Scouts’ Camp Pupukea and the Kaunala Trail, so protecting the ranch from future development would create what preservationists describe as a "green buffer" in a region under constant development pressure.

After some initial resistance, and with the real estate market softening with the recession, Pietsch agreed to sell the development rights to Sunset Ranch forever through the conservation easement. The fair market value of the ranch was estimated at about $6 million and would likely be worth more today, with the conservation easement priced at about $2.4 million when the transaction closed in 2010.

The Maui Coastal Land Trust, acting on behalf of the North Shore Community Land Trust, secured $609,425 from the state’s legacy land fund and $609,425 from the city’s clean water and natural lands program to purchase the easement from Pietsch. The federal government provided $1.2 million through the U.S. Department of Agriculture’s farm and ranch land protection program, mostly because the ranch’s high-quality soil makes it prime agricultural land.

Sunset Ranch was celebrated as a potential model of land conservation for other landowners, a success story in the often losing battle to "keep the country country."

Pietsch’s conservation plan depicted a self-sustaining ranch with horse boarding and riding, farming and the revival of a Native Hawaiian plant nursery.

But as Pietsch explained to the city in a letter last November, traditional agriculture is often not econo- mically sustainable. He said it was impossible to sustain the ranch solely by farming, so his company came up with other uses to cover operating and capital expenses.

Horsemanship and site tours to educate the public on land conservation were expected to account for 83.5 percent of ranch activities this year, Pietsch estimated, and events would make up 16.5 percent. Weddings, luau, parties and fundraisers would account for about 6.7 percent of the events.

Pietsch told the city that Sunset Ranch had 65 reservations booked for such events this year, and that the events were "critical to the viability of the company and our ability to donate the site for charitable causes."

George Atta, director of the city’s Department of Planning and Permitting, responded in a January letter that commercial weddings and other large events are not allowed at the ranch under city land use law and the ranch’s conditional use permits. The city warned Pietsch that continuing to host unpermitted activities is a violation.

In May, a planning firm hired by Pietsch applied for modified permits.

The changes would allow the ranch to host educational tours and retreats for up to 100 people a day — up from 50 — and events such as weddings and receptions, birthday parties, graduation parties and other activities. The weddings and other events would not exceed more than 150 guests and would be limited to an average of two a week.

The ranch also wants the ability to host one photo shoot a day with up to 25 guests.

The planner argued that such events are "clearly incidental to and customarily found in connection with the principal uses of a horse ranch or botanical garden," citing similar events at other ranches and gardens in Hawaii and on the mainland. The city is still reviewing the application.

Pietsch, in a phone interview Friday, said Sunset Ranch is primarily a horse ranch that is working toward a botanical garden in partnership with Waimea Valley. The ranch also has experiments with aquaculture at Charlie’s Pond and has planted coffee trees.

An environmental center may also be developed.

The ranch has also been used by charities and for fundraising events for the North Shore Community Land Trust and the Trust for Public Land.

"I feel I’m just passing through," said Pietsch, who serves on the Trust for Public Land’s Hawaii advisory board. "I genuinely want to share the property with the community."

Some preservationists privately acknowledge that Sunset Ranch may not be the best example of the appropriate balance between conservation and commerce. The bigger picture, however, is that the conservation easement prevents the ranch from ever being subdivided, a permanent value for the public separate from any short-term land use and permitting disputes over commercial weddings.

"In purchasing the easement, we were providing an economic alternative to chopping up the land, which people didn’t want," said Doug Cole, executive director of the North Shore Community Land Trust. "We didn’t have the discussion with the community and the landowner of whether or not people wanted events like that taking place there."

Lea Hong, state director for the Trust for Public Land, said many conservation easements nationally allow commercial activities as long as the agricultural resource is preserved.

"The long-term scheme of these programs is to lock these lands up so they’re not developed," she said. "And that purpose has been accomplished."

Hong and Cole were champions of the $48.5 million conservation easement this year that will protect 665 acres at Turtle Bay Resort on the North Shore from future development, a long-sought victory for the preservation movement.

State Sen. Laura Thielen (D, Hawaii Kai-Waimanalo-Kailua), who was the director of the state Department of Land and Natural Resources when state legacy land money was approved for the conservation easement at Sunset Ranch, said there has to be a public benefit and that land-use laws must be enforced.

"We need to make sure that that’s defined in the documents," she said. "But we have to understand that there’s going to be a private owner over the long term that is going to have to have an ability to manage that land over the long term to honor the conservation easement. So it’s a balance."