A group of middle school students on a field trip encountered some explorers Monday making their way down the Ohio River. These men wore regal military uniforms, the same red, white and blue type that infantrymen wore in the early 1800s.  A captain stepped off a small boat and announced to the group that he was Meriwether Lewis. He introduced his friend, William Clark.

        With a 20-member crew, the group is called Lewis and Clark Discovery Expedition of St. Charles, based in Missouri. It stopped in Cincinnati and Northern Kentucky as part of a re-enactment of the 1803-06 Lewis and Clark expedition, which had huge historical significance for the United States.

        “This is the trial run for 2003,” said Skip Jackson, a Cincinnati native and crew member. “That's the beginning of the bicentennial of the Lewis and Clark expedition.”

        Expedition 2000 is a 626-mile journey on the Monongahela and Ohio rivers from Elizabeth, Pa., to Louisville. With this trip added to previous ones, the Discovery Expedition group will have re-created the Lewis and Clark journey from Pennsylvania to South Dakota.   From 2003 to 2006, the group plans to make the entire trip (from Washington, D.C., to the Pacific Ocean) just as Clark and Lewis did.  The purpose of these voyages is not to explore the United States but to teach schoolchildren and communities about the importance of the first expedition and the impact it had on America.

        “America was a nation in flux,” said Scott Mandrell, who portrays Lewis in the expedition. “There were Irish and English and Dutch. They didn't think of themselves as one tribe.  “When Lewis went west he wanted to redefine what being American was.”

        While many use St. Louis as the starting point of the expedition, Lewis actually started in Washington and headed to Pennsylva nia, where he had his famous keelboat made, and came downriver to meet Clark in Louisville.

        “Lewis and Clark joined there to become (two) of the greatest partners in American history,” said Jim Holmberg, curator of special collections at the Filson Club, Kentucky's privately supported historical society.   The sixth-graders from Summit View Middle School in Kenton County were taking a riverwalk tour when they saw the men in period clothing get out of the boats. A dozen or more of them asked questions and listened as the man portraying Capt. Lewis told stories.

        “We did a lot of studying about Lewis and Clark in the fifth grade,” said Jill Baker, 11. “They were really detailed in what they talked about.”   She knew about the Revolutionary War and the Louisiana Purchase, but not specifics about the men's uniforms and the dog named Seaman that accompanied the expedition.   “It was cool how they looked like what (the men) did when it really happened,” said classmate Steven Dummitt, 11.

        The men camped out in Rabbit Hash downriver and enjoyed an old-fashioned meal at their campsite. They will continue on their journey this morning past Markland Lock and Dam and then on to Carrollton. The group will end their trip in Louisville on Thursday.

EAST LIVERPOOL (AP) -- The Corps of Discovery has returned to the Ohio River to start another exploration of the western United States.

The trip doesn't figure to be as arduous as Meriwether Lewis and William Clark's journey 200 years ago. The crew has a boat with a gasoline engine, a motor home and a satellite uplink to keep the world informed of their progress.

"This is a different mission," said Scott Mandrell of the non-profit, St. Charles, Mo.-based "Discovery Expedition."  "We're telling the Lewis and Clark story, but it's really America's Story. It's a once in a lifetime story for our nation," he said.  Mandrell wants to follow the exact timeline of Lewis and Clark's expedition, meaning this journey should end in mid-November 2005. In the first stretch of the trip, the crew is going down the Ohio River and plans on reaching the Mississippi by mid-November.  About 200 people have signed on for the expedition and will rotate off and on as the journey progresses.  Except for the gasoline engine in the stern, the expedition's boat is in an authentic reproduction of the 19th century keelboat in which the Corps of Discovery began its journey in September 1803.

Most of the 194 residents of Georgetown, Pa., were waiting at the dock Wednesday night when the keelboat arrived. It was supposed to be downtime for the crew, but the town had organized a feast at a church.  Thursday morning, buses filled with schoolchildren began arriving.  "We need downtime to do repairs and just rest, but the people in these small towns turn out to see us. So how can we turn them down?" said Mandrell, a 37-year-old middle schoolteacher from Clayton, Mo., who portrays Lewis.  Departure was delayed while hundreds of children and their parents toured the encampment in a park -- learning about 19th century life, military maneuvers, frontier medicine and blacksmithing.

When the keelboat finally departed for Fort Steuben in Steubenville, Mandrell stayed behind to finish a live Web cast.  Mandrell is a former newspaper editor who changed careers five years ago to be able to have his summers free to train for the trip. He's now on a three-year sabbatical to try to complete the journey to Oregon's Pacific coast.

The boat crew rotates with the ground crew who travel from camp to camp in cars, trucks and campers to set up in advance of the keelboat.   "It's my job to get the boat to Fort Mandan (North Dakota) and train the new crew as they come on, said "patroon" Bob Plummer of Portland, Mo.  Discovery Expedition founder Glen Bishop worked 10 years building the original keelboat, which was destroyed in a fire. The current boat took roughly 10,000 hours over two years to complete.  For Peyton C. "Bud" Clark of Dearborn, Mich., a direct descendant of William Clark, the rain, mud, bugs and bother are well worth it.  "I've focused on this for a long time," Clark said. "This is where I want to be."