Annapolis could soon find itself at a key crossroads--literally--in the burgeoning movement known as "ecotourism."

Federal officials announced last month the development of 16 major trails intended for hiking, biking or other forms of adventuring. Two of the longest and most ambitious trails, according to their plans, will intersect near Maryland's capital city.

A cross-country route, from the Delaware shore to the California coast, will follow the popular Baltimore and Annapolis Trail for a few miles, while a Maine to Florida route will connect the 13-mile path with hundreds of other trails along the eastern seaboard.

County park officials predict the trails will be a huge draw for the growing number of Americans who prefer to do their tourism the nature-friendly way, on foot or bicycle.

"We really have the potential to be one of the pedestrian-cyclists meccas in the nation," said David Dionne, superintendent of the Baltimore and Annapolis Trail. "I think we're going to get a lot of people."

The designation of the 16 "Millennium Trails" is part of an effort by the White House Millennium Council and the U.S. Department of Transportation to celebrate history and geography. Other planned trails will track the Lewis and Clark Expedition, the paths of runaway slaves to free territories, Indian trading routes through East Tennessee mountains and the waterways of the Pacific Northwest.

One trail will beckon travelers to jump on the No. 7 train through Queens, N.Y., to tour a variety of ethnic neighborhoods.

But the biggest will be the coast-to-coast American Discovery Trail and the north-south East Coast Greenway, which will be pieced together from a network of existing and planned bike paths, as well as forest lanes, canal towpaths and country roads, running through every major city along the way.

The 10-year-old Baltimore and Annapolis Trail was an obvious building block for the two trails, Dionne said.

With about 1.7 million visits a year, it is Maryland's most popular park, county officials say.

The asphalt path stretches along the route of the old B & A Short Line Railroad, passing through suburban back yards, quiet woods, commercial strips and horse pastures, with historic railroad structures such as switch boxes and the Severna Park Station along the way.

It's well-known to local joggers, in-line skaters and bikers who may travel only a couple miles of it at a time.

But Dionne said it is already hugely popular with hard-core bicyclists who travel from other states to ride it.

And as part of the East Coast Greenway, which will be completed in about 10 years, Dionne predicted it will become "the urban equivalent of the Appalachian Trail," luring adventurers who want to travel its entire length.

Same with the cross-country route, which will likely cross the Bay Bridge and meander through Anne Arundel's suburban roadways before taking the Baltimore and Annapolis Trail north a few miles and turning westward.

"There are people right now who cycle all across the U.S. on highways," he said. "If you can give them a chance to do this on a trail, and camp and stop off at interesting places along the way, they'll do it."

The designation as a "Millennium Trail" essentially extends the marketing possibilities of the pathways. Trails will carry special markers along the way, and will be promoted on maps and in a national trails database on the Internet.

There is also the probability, but not the specific guarantee, of special funding and federal grants to help upgrade and extend the trails.

The county does not intend to spend extra money on the trails beyond regular maintenance and improvements.

Peggy Wall, executive director of the Annapolis and Anne Arundel County Conference and Visitors Bureau, said her group will start marketing the trails once more of the infrastructure is in place.

She said they probably will double their marketing efforts to Europeans, and especially to the British, who are avid fans of biking holidays.

"It's an opportunity that no one else has, with the two trails intersecting here," she said.