More than a decade after the Fourmile Canyon blaze drove even the firefighters out of Gold Hill, blackened hillsides and scorched trees attest to the Colorado mountain town’s close shave with destruction.

“Because of the wind and the dryness, it took off,” said Chris Finn, who volunteers as the town’s fire chief when he’s not running the local inn. “That day in 2010, I felt that my business and my house might not be here any more.”

Gold Hill’s few hundred residents fled as the fire moved along the ridge above a town that began life as a mining camp during the 1859 gold rush. The firefighters followed when they could not stop the flames swallowing scores of homes.

By the time it was extinguished, the Fourmile blaze had destroyed 169 houses, the most by any wildfire in Colorado history. But that record was broken less than two years later, and then again within days, as the pace of fires picked up.

Gold Hill was once again surrounded by flames last year, which saw a record number of wildfires in Colorado. Now, Finn is bracing for another season of record-breaking fires.

“I’ve lived up here my whole life. You can see the change in the weather,” said Finn.

The 65-year-old fire chief paused in the garden of his modest wooden house.

“I hope that my grandson can be sitting here when he’s my age,” he said.

Finn’s nagging fear that Gold Hill is living on borrowed time is replicated across western states ravaged by some of the most intense wildfires in modern American history. But angst about the immediate threat is accompanied by increasingly urgent questions for communities on the frontline of the climate crisis about the long-term financial cost of survival – who should foot the bill?

Gold Hill has received a state grant to thin out the forest around the town in the hope of slowing if not stopping future fires. But that is a fraction of the cost that the surrounding county says it will take to deal with the impact of global heating.

Boulder county estimates it will cost taxpayers $100m over the next three decades just to adapt transport and drainage systems to the climate crisis, and reduce the risk from wildfires.

The county government says the bill should be paid by those who drove the crisis – the oil companies that spent decades covering up and misrepresenting the warnings from climate scientists. It is suing the US’s largest oil firm, ExxonMobil, and Suncor, a Canadian company with its US headquarters in Colorado, to require that they “use their vast profits to pay their fair share of what it will cost a community to deal with the problem the companies created”.

Boulder county, alongside similar lawsuits by the city of Boulder and San Miguel county in the south-west of the state, accuse the companies of deceptive trade practices and consumer fraud because their own scientists warned them of the dangers of burning of fossil fuels but the firms suppressed evidence of a growing climate crisis. The lawsuits also claim that as the climate emergency escalated, companies funded front groups to question the science in order to keep selling oil.

“It is far more difficult to change it now than it would have been if the companies had been honest about what they knew 30 or 50 years ago,” said Marco Simons, general counsel for Earth Rights International, which is handling the lawsuit for the county. “That is probably the biggest tragedy here. Communities in this country and around the world were essentially robbed of their options.”

Boulder county’s lawsuit contends that annual temperatures in Colorado will rise between 3.5F and 6.5F by 2050 and imperil the state’s economy, including farming and the ski industry.

Extremes of weather are already melting the mountain snowpack, causing increased evaporation and a shortfall in the amount of water flowing down the region’s most important river, the Colorado, which supplies drinking water to the state’s largest cities and irrigation all the way to California and Arizona.

Micah Parkin, founder of an environmental coalition, 350 Colorado, moved to Boulder from New Orleans after it was devastated by Hurricane Katrina.

“We decided to move to higher ground knowing hurricanes are getting more intense, sea levels are rising,” she said.

Within two years, Parkin and her family were put on evacuation notice as the Fourmile Canyon fire threatened the city and she watched the flames from her house. Then in 2013, floods swamped Parkin’s home, the very thing she’d fled New Orleans to escape, when Boulder recorded nearly a year’s worth of rain in just eight days.

Flooding spread over 2,000 square miles, killing eight people, destroying more than 1,700 homes and causing more than $3bn of damage across 14 Colorado counties.

“They were calling it a once in a thousand year event. I don’t believe that. We’ve loaded the dice for more and more of these intense events happening,” she said. “It’s clear that Exxon and these other companies need to be held responsible.”

Exxon and Suncor are alarmed at the prospect of the cases being heard by local jurors with first-hand experience of the impact of global heating in Boulder. The companies are pressing to move the trials out of state courts and into a federal system where laws on deceptive marketing and consumer fraud do not apply.

“Their strategy is to say that these cases need to be in federal court because federal jurisdiction applies. Then they will turn around and argue that federal law provides no remedy,” said Simons. “It is all about a route to dismissing these cases.”

The outlines of the oil industry’s defence have emerged in newspaper columns pushing back against any parallels with big tobacco and claiming it is the end user, ordinary Americans, that causes pollution.

Gale Norton, a former Colorado attorney general who led the state’s litigation against the cigarette companies and later worked as a legal counsel for Shell, has attacked the Boulder lawsuits as a money grab.

“About the only thing that “Big Tobacco” and “Big Oil” have in common … are the deep pockets of the defendants,” she wrote in the Denver Post. Her column highlighted her position as state attorney general, and later as US interior secretary under President George W Bush, but made no mention of her work for the oil industry.

“What is our own individual liability, since annual greenhouse gas emissions amount to almost 20 tons per person?”

The Denver Post editorial board followed a similar line in denouncing the “false equivalence” between the cigarette companies and big oil, and said consumers bore the greater responsibility for the climate crisis.

“The companies didn’t create the demand for fossil fuels. We did through our lifestyles and consumption, including every single member of the communities who now wish to target corporations for a legal shakedown,” it claimed.

That criticism stings in climate-conscious Boulder and other high-income communities that are susceptible to charges of hypocrisy in part because areas of Colorado have some of the highest carbon footprints in the country from heating and cooling larger than average homes.

Max Boykoff, a professor in the environmental studies department at the University of Colorado Boulder, acknowledged the problem, alongside the popularity of high fuel consumption vehicles. But he said that should not be used by the oil companies to absolve themselves of responsibility for a crisis they have played a leading part in creating.

“These lawsuits are one of the tools to hold both these companies accountable,” he said.

Finn said there was no doubt that people moving into the mountains have contributed to the damage from wildfires in part by stopping the natural processes of thinning out the forest.

But the Gold Hill fire chief said the climate crisis was “a big part” of the surging heat and number of fires, and that corporate campaigns to deny the warnings from scientists played an important role.

“The science has been there for years. The problem is that you have half the population who don’t want to believe in science because it means they couldn’t make as much money,” he said.

This story is published as part of Covering Climate Now, a global collaboration of news outlets strengthening coverage of the climate story.