MASO CORTO, Italy (Reuters) - Around dawn, the shepherds gather near the Italian town of Maso Corto and prepare to take their sheep into Austria, along an Alpine track centuries older that the border they are crossing.

Over the next ten hours, they climb 800 meters (2,600 feet) to the Hochjoch pass, corralling their animals over snowfields, along narrow, rocky paths and at one point, across a suspension bridge, single file.

By the end of it, the 1,500 sheep reach their summer pastures in Oetztal - a 16km (10-mile) trek from one valley to another that has survived wars and outlasted empires.

“The first references to the pastures date back to 1360,” says Anton Raffeiner, one of the owners of the land on the Austrian side. Many believe the tradition began when someone from one valley married someone in the other and gave the pasture as a dowry, he adds.

Maso Corto is in the region of Alto Adige, also known as South Tyrol, which became part of Italy after World War One. Strong connections with Austrian Tyrol remain and most people in the region still speak German.

“I have traveled this route more than 200 times,” says 86-year-old Johann Niedermaier, one of the 15 shepherds. None of them work as shepherds full time, and only one will spend the summer with the flock.

This year’s crossing passes without incident. But in the past, the weather has been treacherous and there are always risks. “Nothing has ever happened to the shepherds,” says Niedermaier. “But the sheep...”