In America, our idea of frontier explorers has a Davy Crockett image: rugged men of action, handy with a gun and ready to use it on any inconvenient natives.

Yet the man who first mapped one of the country's most important frontiers — the great Mississippi River system — was a devout French missionary who never fired a shot.

Jacques Marquette (1637-1675) was an adventurous soul, to be sure. Growing up in Laon, France, he heard stories about Jesuit missionaries working with the natives of Quebec, and meeting success and hideous death for their efforts. Despite (or perhaps because of) such dangers, Marquette decided early that he wanted to be a missionary.

According to Raphael Hamilton's "Father Marquette," Marquette joined the Society of Jesus when he was 17 and soon wrote to the head of the order telling him of his ambition. However, in a Catholic order desire isn't enough to decide a vocation. Ultimately, your superiors decide the course of your life. In this case Marquette was told he was too young, so he observed his vow of obedience and continued training.

As a novice, Marquette went about community service such as teaching and tending the sick, as well as spiritual disciplines such as contemplation and prayer. He earned high praise from his superiors for his spiritual devotion and generosity.

Maybe too high praise. In 1665, when he was 28, Marquette was put on track to become a "professed father." The exalted type of priest helped shape the order's policies.

On A Mission

That wasn't what Marquette wanted. He still wanted to be a missionary, not an administrator. And the course toward professed fatherhood took four to six years, which seemed like forever. So he wrote to the head of the order pleading his case.

But again, the response was ambivalent. He didn't get a no, but bureaucracy crawled at its usual glacial pace. Marquette swallowed his frustration and excelled at his work.

His break finally came about because of international politics. France, England and Spain were colonizing the Americas at that time, and a superpower rivalry was heating up. The king of France called for more missionaries to push deeper into the frontier and enlarge France's claim. When word came to the Jesuits, they knew who to pick: Marquette.

The novice was fast-tracked to ordination and finally reached Canada in 1666. Initially he went to an established mission at the site of what is now Montreal and began studying American Indian languages and cultural customs. He proved remarkably adept at this; within two years he had mastered six local languages.

In 1668, Marquette moved out to the edge of the Frenchman's known world. First he went to Sault Ste. Marie, on what is now the Canada-Michigan border. While there, he heard about the tribe called the Illinois and the giant river it lived on named the Misi sipi, the "Father of Waters," with countless tributaries.

In Sault Ste. Marie, Marquette met Louis Jolliet. Jolliet had also studied with the Jesuits, but he decided against the religious life and went into the fur trade. The two men discussed the fabled river and its political implications. If it emptied into the Atlantic Ocean, the English would soon find it and get the fast track to the American interior. If it emptied into the Gulf of Mexico, the Spanish would probably find it and do the same. If the French were to get there first, they would have to do it from the north end.

Marquette and Jolliet both wanted to go. They also recognized that they needed each other. Jolliet had the hunting and navigating experience; Marquette had the languages and the trust that most Indians afforded the "Black Robes." Yet both had other duties. Jolliet had a business to run, while Marquette was soon called to rescue a crumbling mission in northern Wisconsin.

Still, neither man forgot the river. While in Wisconsin, Marquette met a man with the Illinois tribe and quickly added another language to his repertoire. Thanks to that, he gathered as much information about the river as he could from the locals. In 1670, he finally put in a formal request to go on an expedition.

The request was approved, but other delays came along. Marquette had promised his mission community that he wouldn't leave it without a replacement priest, and none was forthcoming. Then violence broke out between the mission dwellers and the neighboring Sioux, forcing Marquette and his flock to relocate.

But Marquette showed the same fidelity to his goals that had made him a missionary in the first place. In the spring of 1673, he, Jolliet and a small group of other white men and Indians finally set out.

The mission Indians were still afraid of the Sioux, so they reached only the head of the river before turning back. That left the whites to go alone into unknown territory that had potentially hostile people.

Despite the imperial backdrop of the journey, Marquette was determined to represent his God as nonviolently as possible. When his group came to its first village, he and Jolliet left the party and approached alone and unarmed.

Fortunately, the Illinois tribe heard it might be expecting Black Robes at some point and gave the travelers a friendly reception. Here and at other points along the way, Marquette used his knowledge of native languages and customs to forge relationships, giving speeches, exchanging gifts and trying to explain the tenets of his religion.

Things got dicier as the crew headed south of Illinois tribal territory and into lands of unknown Indians. But even here, Marquette stuck to his pacifist approach. When the group floated into the land of the Mitchigamea, the warriors armed with arrows piled into canoes and stormed out toward the travelers.

Marquette ordered his companions not to touch their guns. He stood up holding his peace pipe aloft, calling greetings in every language he knew.

Finally two elders called off the attack. Even more fortunately for Marquette, one of them knew a little of the Illinois tribal language. This elder took the travelers to the main town in the nation, Akansea (whence the name Arkansas). There they met a better Illinois speaker who filled them in on current events.

As it turned out, some of the neighboring tribes already had contact with the Spanish and had been buying guns and other goods from them. The Mitchigamea hoped the Frenchmen could provide them with guns also.

Heading Back

Marquette didn't provide guns. He also realized that the Spanish presence brought a greater danger than any local tribes. He and his companions decided to head back home.

Marquette contracted an illness and didn't live long after his return to the north, but he imparted a gift that outlived him: his travel diary.

Along the journey he kept meticulous notes of everything — compass directions, weather, local people, local food, even handy tips like how to fend off mosquitoes at night. He wanted others to follow where he had gone.

Eventually, the French wound up surrendering the Mississippi Valley with the Louisiana Purchase.

Still, Marquette set a standard for peaceful exploration.

BY AMY REEVES