Travelers who frequent the winding mountain roads of Southern Appalachia know that, every few miles, they're going to pass yet another small Baptist church sitting close to some rushing water. It's all about location, location, location.

Why would a preacher want to baptize a new believer in a heated, indoor tank when he can dunk them in the powerful, living, frigid waters of the river that created the valley in which his flock has lived for generations? There's no question which option the self-proclaimed Primitive Baptists will choose, even if it adds an element of risk.

"Among Primitive Baptists, you almost always see two ministers when they baptize someone -- one to do the baptism and one to hold on. It's even become part of their unique liturgical tradition to have two ministers there," said Baptist historian Bill Leonard of the Wake Forest School of Divinity in Winston-Salem, N.C.

"As the saying goes, you could get baptized and go to heaven on the same day if there wasn't somebody there to hang on so you didn't wash away and drown."

This is the kind of old-fashioned faith that Americans are used to seeing in paintings of frontier life or grainy black-and-white photographs from the days before interstate highways, shopping malls, satellite dishes and the Internet. Appalachian religion has played a dramatic role in American culture, helping shape our folk art, Scotch-Irish history, roots music and a host of other subjects.

The question, for Leonard and many other scholars, is whether the rich heritage of "mountain Christianity" will play much of a role in the nation's future.

"Increasingly," he said, "our modern forms of American religion and our mass media and culture are sucking the life out of one of our most distinctive regions."

While the region contains religious groups with European ties, the most important fact about the common Appalachian churches is that they are uniquely American.

For outsiders, this can be very complex territory.

The Calvinist, Primitive Baptists are not the only Baptists whose sanctuaries dot the landscape of the 1,600-mile-long strip of mountains that run from Eastern Canada down to the high hills of Alabama and Georgia, cresting at Mount Mitchell in the heart of North Carolina's Black Mountains. There are Independent Baptists (of various kinds), Free Will Baptists, Old Regular Baptists, Missionary Baptists, Southern Baptists and dozens of other brands.

Even the Primitive Baptists are a complex bunch, noted Leonard. There are some who avoid wine and some who make their own. Some refuse to hire professional pastors or to send their preachers off to seminary, fearing they will be corrupted. There's even a small body of Primitives -- critics call them "no-hellers" -- who insist God's love is so strong that everybody ends up in heaven, no matter what.

Then there are the various kinds of Pentecostal-Holiness churches, including the rare -- but world famous -- congregations in which believers handle snakes, sip poison and wrestle with demons.

Some "Oneness" Pentecostal believers baptize in the name of Jesus, alone, while others embrace the traditional Trinity of God the Father, Son and Holy Spirit. In an academic paper entitled "Looking for Religious Appalachia," Leonard noted that he once heard a Trinitarian Pentecostal preacher explain that doctrinal feud in terms anyone could grasp: "Jesus had a Daddy. He wasn't no bastard."

"Case closed," wrote the historian.

Ironically, some of the most powerful forces that threaten these churches are the efforts of outsiders to help the region -- such as missionaries sent to evangelize the locals or social-justice activists who want to help the locals escape their own way of life. Then there are the softer forms of Evangelical Protestantism that arrive through television, mass-marketed gospel music and those new, transplanted megachurches that keep sprouting up like suburban superstores.

Thus, the stark "Sacred Harp" hymns of the shape-note era gradually gave way to the cheery gospel quartets of the radio era, which were then blitzed by the pop-rock "praise bands" of the Contemporary Christian Music era.

What happens when the mountain churches and their traditions are gone?

"Appalachia still exists and it remains something to celebrate," said Leonard. "Still, what's happening there is a danger signal to us all. ... What was once pristine wilderness is becoming an exploited region. Tragically, a crucial element of America's religious history and heritage if being lost, as well."