When a teenager hurled fireworks into a parched canyon near one of Oregon's most scenic hiking trails, sparking a cloud of smoke to rise up toward him and his friends, some in the group reportedly giggled and recorded video, oblivious to the danger.

What came next was a bushfire that raged through the Columbia River Gorge and, eight months later, a court order mandating the teen pay more than US$36 million ($51m) in restitution.

Hood River County Circuit Judge John Olson in an opinion released today acknowledged that the teen could not pay that full amount.

But the damage caused by the September 2 fire was substantial: After the firework ignited dry bush, a blaze spread to more than 19,425ha, wrecking many parts of the gorge's recreation area and costing firefighters at least US$20 million, the Oregonian reported. It would be known as the Eagle Creek fire, which burned for two months and was not 100 per cent contained until November 30.

The fire endangered popular landmarks such as Multnomah Falls and destroyed the Oneonta Tunnel on the Historic Columbia River Highway, about 50km east of Portland. It forced hundreds of people to evacuate to cities between Portland and Hood River, Oregon, closed the Interstate 84 for 10 days and threatened 5000 homes and buildings, according to the Oregonian. At least four homes were destroyed.

In Cascade Locks, a summer tourist destination near the Columbia River, businesses took an estimated hit of more than US$2 million, the Oregonian reported.

The teen's mother told the Oregonian in November that the fire was "a trauma" for her 15-year-old son, who authorities at the time suspected caused the fire, and that "It was his mistake." She didn't elaborate, fearing public backlash against their large Ukrainian family and the boy's school-age siblings.

In February, the teen admitted to eight counts of reckless burning of public and private property, two counts of depositing burning material on forest land, and counts of second-degree criminal mischief and recklessly endangering another hiker, according to court records.

He was sentenced to five years of probation and 1920 hours of community service with the US Forest Service, according to the Oregonian. He was also ordered to write apology letters to 152 people who because of the flames were trapped on the Eagle Creek trail, as well as to the city of Cascade Locks, the Forest Service, Oregon State Parks, the Confederated Tribes of Warm Springs, and the state's transportation department, among other groups.

His lawyers have said that the US$36 million restitution amount is steep, arguing that such a number violated the US and Oregon constitutions, believing the amount to be "cruel and unusual punishment," according to court records. But Olson in his opinion wrote the restitution was "clearly proportionate to the offense because it does not exceed the financial damages caused by the youth."

The restitution, he wrote, includes more than US$21 million on behalf of the Forest Service, US$12.5 million to the Oregon Department of Transportation, more than US$1.6 million to the Oregon State Fire Marshall, more than US$1 million to Union Pacific Railroad and varying amounts to Oregon State Parks, Allstate Insurance and Iris Schenk, who lost her home in the fire.

Olson noted in his opinion that the teen has some options for paying the millions off. The court could authorise a supervising authority to create a payment plan, he wrote.

He also said it was possible for the teen to pay restitution for just 10 years if he successfully completed his probation, complied with payment plans and did not commit any other offences.