On a cold winter's day, with white clouds scudding across the blue sky and patches of snow clearly visible, the rugged desert hills of south Arizona are a spectacular backdrop.
And they are the battleground between industry and environmentalists.
For a long time in Arizona, copper was king. At the end of the 19th century, mines were built to get to the metal. Towns sprung up around the mines. People moved west to live in the towns and a state was established and grew.
In many places, as the price of copper dropped and the easier seams were tapped, the mining companies shut up shop. Small towns struggled as all that was left behind was a huge hole in the ground.
With copper prices soaring, demand accelerating and new technology bringing harder to reach deposits closer, the miners are heading back with promises of putting billions of dollars into the local economy and providing thousands of jobs. But locals aren't exactly waiting with open arms.
At one proposed site, 50km south of Tucson, Rosemont Copper, the subsidiary of a Canadian-owned firm, wants to open a huge open pit mine high in the Santa Rita mountains.
It would gouge a hole in the ground more than a kilometre wide, more than a kilometre long and almost half a kilometre deep.
The company insists the mine is essential, not just for what it would do for industry locally, but for the national economy.
Rod Pace has been a miner for almost three decades and is now in charge of the Arizona project. As we stand overlooking the site he tells me: "This is a world class deposit. Once it's up and running it'll produce ten percent of US copper probably for the next 20 or so years. And it'll produce a lot of jobs for this economy about 2100 new jobs in this area."
The company knows about the environmental objections. It's spent seven years and tens of millions of dollars trying to get the project up and running.
It says it will be the most modern copper mine in the world. It will use green technologies, computer systems and environmental friendly vehicles. And it will even use cows to return some of the land back to its natural state.
But many local people aren't buying that and with many environmental groups they are actively lobbying regulators who will make the final decision on whether the project goes ahead.
Randy Serraglio works for the Centre for Biological Diversity. He's already beaten off one plan to exploit the Santa Ritas and thinks he will be successful again: "There's a long list of reasons why this mine should never happen.
"It's a threat to air quality, to water quality and quantity, it's a threat to the wildlife. It's a threat to the economic and physical wellbeing of the people who live near the mine."
And he dismisses the idea of the mining company taking steps to limit the damage it decades long operation will do, as a bad joke. "It's like dropping a nuclear bomb on that area… it'll never be the way it is now and there’s no way to mitigate against that." he says.
As copper companies left after the last boom, the Arizona economy looked for alternatives, diversified and matured.
There are wineries and farms and bed and breakfast places all geared up to exploit the stunning scenery.
A recent report suggested in the two counties which would be most affected by the mine, recreation and ecotourism are now worth almost $3bn to their economy, and the worry for campaigners like Frances Causey is that could be hit and hit badly.
"The very large Rosemont Copper public relations operation would like southern Arizonans to believe that this mine will bring jobs," says Causey.
"No doubt it will bring some jobs but if you really drill down, pardon the expression, when you really drill down and look at the numbers, they're talking about 400 direct jobs.
"That's less than one tenth of one percent of the jobs in southern Arizona, not to mention the jobs that will be destroyed."
The mine plan has already received many key permissions, the latest from Arizona's Department of Environmental Air Quality which said emissions from the proposed mine would not violate federal standards for carbon monoxide, nitrogen, sulfur dioxide or fine and large particles.
Strictly speaking, only one more permit is required and that will come from the US Army Corp of Engineers and will deal directly with the question of water on the site, how it will be used and if it would impact the supply to local communities.
And even if that is given, then the Environmental Protection Agency can veto the development.
Both sides are working hard to convince regulators and public opinion they are right. Yet this is a battle that will almost certainly be settled in court.