Until the late 20th century, there was no road connecting it to the outside world. Travel meant days of walking over mountain passes. Each winter, heavy snow sealed the valley off for months. Supplies came in on foot or by mule.

The border police station here was established in 1964, though a military presence dates back to 1952. For much of its history, the role of the station's staff was as basic as it was demanding: patrol the border, maintain order and help people survive in a place where geography shaped every aspect of life. Over 74 years, eight officers have died in the line of duty. The work, though, has never been limited to security.

"We've always been doing more than guarding the border," said Li Xiaojun, a former station chief who served from 2016 to 2021. "We were part of building this place — step by step."

The changes came slowly at first. In 1999, a rough road finally reached Dulongjiang township, ending the region's complete isolation. But it remained unreliable, often cut off by landslides or snow. It was not until 2014, when a tunnel through the Gaoligong Mountains opened, that the valley became accessible year-round.

"The difference is hard to describe," Li said. "Before, everything had to be carried in. Now, people can drive out in a few hours."

With access came opportunity. Tourists began to arrive. Local products — especially tsaoko, Chinese black cardamom, also known as caoguo, a spice grown in the region — found markets beyond the valley. Motorcycles and, later, private cars became common. Income rose. In 2018, the Derung people, once among the poorest groups in China, were officially lifted out of extreme poverty.

In 2019, the township's Party committee wrote a letter to President Xi Jinping to share the good news. In a reply dated April 10, 2019, Xi congratulated them and stated that poverty alleviation is just the first step, with better days yet to come. He expressed hope that the villagers would continue their efforts, work hard, and unite to build their hometown well and guard the border well, striving to create a brighter future.

For Li, the message captured something they had long understood.

"Protecting the border and developing the community are not separate things," he said. "They happen together."

In Dulongjiang, that principle is visible in small, daily interactions.

In addition to their primary duties such as processing documents, maintaining public order and patrolling the borders, the police also provide free services to the villagers, such as traveling to remote villages to take photographs for official paperwork, giving haircuts and helping with some farming tasks, saving people the cost and time of long trips. They mediate disputes — often between relatives in tightly knit communities — preferring conversation over strict legal enforcement.

"In a place like this, you can't just apply rules in a dogmatic manner," said Gou Guowei, a former instructor at the station. "You have to understand local residents' lives."

He recalled introducing what officers call "hearthside mediation", where mediators, police officers and involved parties sit around the fire to resolve conflicts in a more familiar setting. He said, "That's where people feel at ease, and that's where you can really talk."

The relationship runs both ways. Residents, in turn, rely on the police not only for safety, but for help in emergencies.

During one winter, when snow blocked the road, Li led a team to transport a student with appendicitis to a hospital, clearing ice along the way. What would normally take an hour stretched into several.