Every spring, hunters and herdsmen light small fires as they camp in the windswept countryside or beside the huge coniferous forests that lie in the north-west of Mongolia. And every spring, some of these fires are left alight. Unattended, they rise, rapidly consuming the dry grass or trees, until they are blazing out of control.
Eventually, enough people are mobilised to beat down the flames, using the only tools they have had for centuries - clothes tied to sticks, brooms and water from rivers or wells. Every year people are injured as they fight or flee these fires.
Urban Mongolians shrug off the blazes. They happen every year. The people in the countryside are careless. But this scarcely populated country (2.3 million at the last count) has been stunned by the ferocity of this year's fires.
Nearly 300 have been recorded this year and about 25 are still burning. A quarter of Mongolia's forests have been burnt to the ground. At least 19 people have lost their lives, including a 16-year-old firefighter. Generations of livestock have been wiped out, or burnt so badly they have had to be destroyed. Hundreds of families are homeless, their traditional round- tent dwellings quickly consumed in the fires.
Some families have resorted to sleeping in the open, where, even in May temperatures can drop to -10 degrees at night.
It is the sheer size of Mongolia that has allowed these fires to rage. It is the size of Western Europe. Outside the big cities, communication is unsophisticated and roads are bad.
The fires damaged thousands of communication line posts this year. Reports of fires were delayed, as whole communities live without telephones. At times, all people could do was watch their land go up in smoke.
The area close to the capital, Ulan Bator, in central Mongolia, has also been badly damaged. Terelj nature reserve lies only 45km north-east of Ulan Bator. It is a popular haunt for tourists and the 900 or so foreigners who live in the capital.
The fire at Terelj was small compared to many which have been burning across the country since February. It spanned roughly 16 by 10km (9 miles by 6 ). But locals, including children, fought the blaze unassisted for over a month, before 500 volunteers were drafted in from the nearby city of Nailah.
They fought the blaze with sacks and water from the nearby river. "Weather- modification pellets", made from dried carbon dioxide, were fired from an old Russian cannon into the low-lying cloud. This was to induce the snow which had finally been forecast. Forty-eight hours later snow had fallen, and the fire had been extinguished.
Although we arrived at Terelj towards the end of the firefighting operation, the ground was still smouldering, as though ready to reignite, as has happened at hundreds of sites across the country. Fires apparently extinguished have fed on the high winds and parched yellow grass and once again blazed out of control.
Thousands of Mongolians have spent weeks sleeping close to the blazes, breathing in smoke that prevents them from seeing 10ft in front of them. Winds have changed direction so rapidly and with such fury, that these inexperienced volunteers, who include prisoners released from a jail, have fled from the blaze, unable to save anything. At least one person died on horseback, trying to gallop beyond the flames.
The brief television news reports cannot convey people's shock at losing their homes and livelihoods.
Towards the end of April, the world was finally alerted to the tragedy. Trucks loaded with aid are lurching across the Mongolian steppe. Tents, fire-proof clothing and food are gradually reaching remoter corners of the country. Local relief operations have moved a staggering 250,000 livestock from charred, ruined land, to fertile pastures.
Recent estimates by the government admit environment damage caused directly by the fires will cost $2bn (pounds 1.3bn).Funds are needed to implement a warning system in rural areas to prevent the tragedy from recurring. If no preparation is made for next year, the spring of 1997 may not bode well for this fragile land.