In more than 30 states across the nation, in summer swelter and now in autumn cool, Greg Zanis is erecting his crosses. He calls them his "babies" and sometimes he sleeps on them in the bed of his truck.

When he gets to where he's going, he makes more. By his count, he has already made about 3,400 crosses--an impressive number, but far too few for all the souls in America.

"I'm not exactly sure what this commitment is that I've started," Zanis says, dragging a hefty extension cord across a church lawn in Arnold, Md., Tuesday so he can power his saw. "But I've started it."

Six months ago, Zanis was a carpenter who built houses in Aurora, Ill., a born-again Christian who occasionally erected eight-foot-high wooden crosses on behalf of people who had recently died.

Then Columbine happened, and Zanis found his mission.

Now he has a scheduling agent, and he's booked solid across the country until Sept. 26, 2000. This week, his mission has brought him to Maryland, to Broadneck Evangelical Presbyterian Church in Arnold, to preach the message that Columbine happened "because we've forsaken the Lord."

Zanis first flashed into the news right after the school shooting in Littleton, Colo., last April. He got into his truck, drove to the town and built 15 human-size crosses on a hill near Columbine High: 13 for the students and teacher killed, and two for the killers. While the father of a victim angrily tore down the crosses for Eric Harris and Dylan Klebold, the other 13 became a pilgrimage site, decorated by mourners with writing, pictures, balloons, ribbons.

Not long after that, Zanis hit the road. He took the 13 original crosses with him and two replacements, and started visiting a circuit of towns and cities across the country. He stopped working, began driving through the night, began talking with his wife and kids more often by phone than in person.

These days, he is often away for a week or two at a time, then back in Aurora for a few nights. And wherever he goes--Georgia, New York, Texas, Utah--he uses donated lumber to build more crosses for local fatalities, and to build replicas of the Littleton crosses that the towns can keep.

Zanis has brought his crosses to the Arnold church at the behest of a local nonprofit group called Camp Blaze. He'll stay until tomorrow. On Tuesday, he set the crosses by the roadside--13 standing and two plain ones prone--and yesterday, with his electric saw and metal ruler, began teaching groups of local children how to build more. In time, Zanis says, if he teaches enough people, he could achieve his goal: a cross for every person in America.

At first glance, Greg Zanis isn't noticeable as he digs holes and hefts lumber on the front lawn of the church. He wears a grungy yellow T-shirt, jeans and a sagging tool belt, and--despite his talkative manner and his predeliction for hugging strangers--few new arrivals at the scene seem to pay him much mind. He doesn't look like a man on a mission. He looks like an ordinary guy who might be helping a man on a mission.

Until he speaks. "I live Columbine, I breathe Columbine, I eat Columbine," he says, grinning. He is part hyperbole and part disarming honesty. Since starting "the tour" last May or June, he has run up $25,000 in credit card debts, he says. He began accepting donations only about two months ago, he says, and since then, he has gotten $7,000--barely enough to pay for gas. And if the more personal details of his life get lost in the sleepless nights and financial strain and vigor of this enterprise, so be it.

How old are your kids, Mr. Zanis?

"I don't know all my kids' ages."

When were you last home, Mr. Zanis?

"I don't remember."

But this cause didn't really start with Columbine. It started three years ago with one horrible, personal experience.

Zanis, 48, learned his trade--carpentry--from his wife's father, with whom he became best friends. When his father-in-law, a landlord, was robbed and murdered in 1996, Zanis found the body. He was devastated.

From then on, Zanis began making crosses--for murders, highway accidents, untimely deaths--erecting them at the places where the deaths occurred. He became friends with the cops and the county coroner. He began using his weekends and his spare time because it seemed that with each wrongful death, God was disappearing from the world.

No wonder, he says: They took prayer out of school, and the Ten Commandments, too, and they even took away the manger that used to sit right across the street from his dad's house in Geneva, Ill.

With each cross, Zanis felt he was putting God back. Not in the manner of a minister. Not the way his father, a Greek Orthodox priest, might have done it. No, Zanis felt he was a one-man grass-roots operation, communicating God through his calloused hands and his lumber.

"Those priests never were out there healing the people like I am."

If this mission makes Zanis forget the death of his father-in-law, the man whose demise made him feel "[not] suicidal but I didn't want to live," then so much the better.

"Do you see me mourning?" Zanis says. "I don't have time for self-pity."

In Arnold, as everywhere, Zanis is far too busy talking to the curious, the sympathetic, the spiritual.

Jan Johnson of Churchton comes up to Zanis, receives his hug and says, "I know the families don't want you to have a cross for the shooters." Then she opens her palm and inside are two tiny beaded crucifixes she made with her own fingers for Klebold and Harris, to signify that they are forgiven.

Zanis leads the woman to Cheryl Carnwath, the leader of Camp Blaze, and says, "Cheryl, can I have a quick prayer here?" Another woman--another stranger--joins them, and the foursome join hands, bow their heads on this lawn and pray.

Later, Johnson and Zanis dig holes in the ground beside the killers' crosses and drop her handiwork in. They fill in the dirt.

Zanis's mission is straight and simple. He will do this until he can't anymore, he says. The Lord will provide. Eventually, he is planning to purchase 20 acres near Columbine and set up his crosses there permanently. But even then, there will be more deaths and more crosses to build. He does not question his purpose.

Back in Aurora, Susan Zanis, 47, is talking about the impact of her husband's absence on herself and her five children, whom she home-schools. The eldest is 19, the youngest is 6. She is counting on Greg coming back for Thanksgiving and staying a few weeks.

He "is our only source of income right now and it's hard for him to say no, but I mean, you have to be realistic and look at your [own] needs, too," Susan Zanis says. "I'm kind of hoping he won't have to keep doing this because we do need him here, to put it bluntly."

Then, she adds: "It's brought me closer to the Lord."

Ten minutes later, the man on the mission calls. He spoke with his wife, who spoke to a reporter, and he wants to know what Susan said.

"Is she all right with me doing all this?" By this, he means "the tour," all six months of it, the purpose, the penury, his absence.

"Did she say I'm neglecting the family?" he asks.

They don't talk about it, he says, because he's afraid she'll want him to come home.

CAPTION: Since the Columbine tragedy, Zanis travels the country with his crosses. Here he prays in Arnold, Md.

CAPTION: Greg Zanis hugs Jan Johnson, who came to see the Columbine crosses.