ALBUQUERQUE, N.M. -- Travelers once used oxen to travel the nearly 1,500-mile El Camino Real de Tierra Adentro trail from Mexico City to Santa Fe.

Now they can use a mouse.

The U.S. Bureau of Land Management, as part of its celebration of the 100th anniversary of the Antiquities Act of 1906, has put together a history tour via computer of the Camino Real.

El Camino Real is a designated national historic trail, as well as the only international trail recognized in the U.S. trail system.

During its peak as a wagon road through the early 1800s, El Camino Real led settlers north, promoted trade and fostered an exchange of people and ideas that led to the vibrant culture that is the American Southwest, according to the Web site, www.blm.gov/heritage/adventures. Click on the tour link titled "Royal Road of the Interior Lands" on the left side of the site.

It was designated as a royal road in April 1598 when the first Spanish colonists from Mexico reached a shallow ford of the Rio Grande near present-day El Paso, Texas. The trail, which had begun as a path that threaded among the native communities of the Rio Grande, eventually developed into a dusty wagon road in New Mexico and a cobblestone highway farther south.

Today's computer visitors start with a map of the trail from Mexico City to Ohkay Owingeh Pueblo north of Santa Fe.

Along the way, they can hear audio clips from historians and go to links that include the oldest public building in North America; the staging area for Union soldiers heading for the Civil War battle of Valverde; the signing of the Gadsden Purchase, which brought southern New Mexico territory to the United States; Billy the Kid's visit to Old Mesilla, New Mexico's first Spanish capital; and the Bosque del Apache National Wildlife Refuge.

The trip took the early travelers six months along rugged deserts, through Indian lands and over the steep volcanic La Bajada south of Santa Fe. Forts were built along the trail after the Americans took over the Southwest after 1846.