Former guesthouse owner Tenzing Lama remembers when foreign tourists thronged Nepal's Langtang valley, trekking through the breathtaking Himalayan wilderness and soaking up the tranquility.

But the massive earthquake that ripped through Nepal one year ago killing almost 9,000 people, obliterated the valley, part of the country's oldest national park, along with the tourism industry on which it relied.

Villagers have since returned to the valley and started the Herculean task of clearing trails and rebuilding homes and guesthouses flattened in a massive quake-triggered avalanche.

But as is the case in the rest of the country, trekkers and backpackers have so far stayed away, leaving already desperate locals facing an uncertain future.

"Every family here depended on tourism. One hundred percent of our economy came from that," said Lama, 45, who grew up in Langtang village which was decimated by the avalanche that sent huge blocks of ice barrelling through the valley.

As a boy, Lama often saw foreigners passing through his village, where they would sometimes stop for a meal or an overnight stay, sharing chocolates with local children, during days-long trekking expeditions.

By the time he built his own guesthouse in 2000, the valley was enjoying a tourism boom, with Langtang village alone hosting dozens of lodges that served up everything from Nepali staples of lentils and rice to trekker favourites like apple pie.

When the avalanche struck on April 25, killing his brother, niece and nephew and burying hundreds of neighbours and friends in rubble, Lama and other survivors were evacuated to Kathmandu until the valley was deemed safe.

The disaster killed 283 locals and 43 foreign visitors in the valley, according to police.

Many villagers like Lama have since taken rebuilding matters into their own hands, carrying sacks of supplies along steep, hilly paths and repairing trails and lodges on their own.

"I had nothing left... but then, as time passed, I thought I should go back, I should try and rebuild my life, my guesthouse," the father-of-four told AFP.

- Terrified trekkers -

When the earthquake struck, triggering avalanches and landslides, many backpackers were stranded for days in remote, mountainous areas accessible only by helicopter.

Terrified foreigners fled the Himalayan nation and many prospective tourists cancelled bookings, even avoiding popular trekking routes such as the Annapurna trail, which escaped the carnage unscathed.

The industry's annual revenues fell by 32 percent in 2015, according to the Nepal Tourism Board, dealing a devastating blow to the economy of the already impoverished country.

Nepal relies on tourism for around four percent of its gross domestic product, with the industry providing 3.5 percent of employment.

Tour operators say their businesses are unlikely to recover this year.

"When you lose 85 percent of your business... basically that's 85 percent of your cash flow that's gone," said Ashok Pokharel, president of the Nepal Association of Tour Operators.

In a bid to lure visitors back, authorities decided to hand out free mobile SIM cards to backpackers ahead of this year's spring trekking season, hoping to reassure them that they would be helped if disaster struck.

The government also called in international experts from Miyamoto, a US-based firm, to assess the safety of the Everest and Annapurna trekking routes in the months following the quake.

Engineers ruled that both routes were largely unaffected and safe for travel.

In the Kathmandu Valley, masons have begun to repair quake-hit historic monuments in an effort to restore and preserve Nepal's rich architectural heritage, which dates back to the fifth century and remains a key tourist attraction.

"The government is rebuilding -- a few sites are already built and a few are being built (and) will be completed in one to three years", said Nepal Tourism Board CEO Deepak Raj Joshi.

But far from the capital, Langtang shows little sign of government activity -- other than an army checkpost at the bottom of the main trail -- and few visitors have come back despite cleared trails and a handful of new or restored guesthouses.

In his village, Lama surveyed the rubble-covered landscape where his eight-room lodge used to stand, and wondered whether his gamble would pay off.

"We will somehow rebuild our guesthouses, we will borrow money, we will do whatever we need to do. But what if the tourists don't return?"

"Where will we go then?"