JUNEAU, Alaska - The group promoting a massive gold-and-copper prospect near Alaska's Bristol Bay said Tuesday they plan to press on with their work, despite passage of a ballot initiative aimed at stopping the controversial Pebble Mine.

Unofficial results released by southwest Alaska's Lake and Peninsula Borough late Monday showed a vote of 280-246 in favor of a ban on large-scale resource extraction activity, including mining, that would destroy or degrade salmon habitat.

The measure was targeted at Pebble Mine, which opponents fear could fundamentally change the landscape and disrupt, if not destroy, a way of life in rural Alaska and threaten one of the world's premier salmon fisheries.

The mine would be directly above Iliamna Lake, the largest producer of sockeye salmon in the world. Critics have said the potential footprint of the project could cover 15 square miles, with an open pit and network of roads and power lines.

Project officials have said repeatedly that a pre-feasibility study and a formal mine plan haven't been completed. But supporters have said it could create up to 1,000 long-term jobs in economically depressed rural Alaska.

Project spokesman Mike Heatwole said there has been a concerted effort to cast the project as a choice between mining and salmon. But that isn't the case - the "core value" of the proposed Pebble Limited Partnership mine would be its co-existence with the fishery, he said Tuesday.

The mine is a joint venture of Canada-based Northern Dynasty Minerals Ltd. and Anglo American PLC of the United Kingdom. The companies have spent hundreds of millions of dollars scoping out the deposit, which Northern Dynasty has described as the largest undeveloped deposit of its type in the world, with the potential of producing 53 billion pounds of copper, 50 million ounces of gold and 2.8 billion pounds of molybdenum over nearly 80 years.

The partnership had sought to stop Mon day's vote, arguing in part that the measure would improperly bypass the role of the local planning commission. But a state court judge refused, noting that the Alaska Supreme Court has given deference to initiatives absent proof they would do something unlawful. The judge instead put the case on hold until next month.

The state attorney general's office has also said the initiative would enact an ordinance that's "unenforceable as a matter of law."

The partnership hasn't decided whether to contest the election or seek a recount, he said. But the group does plan to challenge the initiative in court, Heatwole said.

Art Hackney, a spokesman for initiative supporters, said his side expects to do well in the court fight. But he expects the companies will "throw everything they can" at Monday's vote to try to get it invalidated.