ONAWA (AP) -- A $5.2 million interpretive center under construction in Lewis and Clark State Park will not be completed in time for the bicentennial anniversary of the explorers' trek through the area.

The Sioux City Journal reported in a copyright story that the 15,300-square-foot center has already missed a July 1 targeted completion date.

Now, officials say it still won't be ready by Aug. 6, when a three-day series of events kicks off to commemorate the 200th anniversary of the explorers' stay on the Missouri River near this northwest Iowa town.

Thousands of history buffs are expected for a number of bicentennial celebrations, including one in Sioux City on Aug. 20.

"Now we hope to get it done by winter," said Stephen Allen, co-chairman of the committee that planned the center. "We will get it done, we just haven't been able to get it done in time for the bicentennial."

Organizers said the construction has been stymied by financial problems. The Omaha-based construction company building the center hasn't been at the site since June 18, Allen said, and the facility is only about two-thirds finished.

The interpretive center is designed to be home to the only full-scale, authentically designed keelboat and pirogues - replicas of ones used by Lewis and Clark. With so many tourist centers along the explorers' 4,000-mile path, Doug Hartman of Hartman Historical Services of Omaha said it is important for each to be distinctive to make a mark.

Onawa Chamber of Commerce director Jill Johnson said plans to commemorate Onawa's tie to the expedition have been going on for years. She said the delay was a setback, but doubted it would diminish the number of visitors to Lewis and Clark State Park.

"I don't think that is going to hinder people coming out," Johnson said. "Regardless of whether we had an interpretive center or not, we are going to have a bicentennial … it was just going to be an added feature."

Richard Bergt of Springfield, Ill., was at the state park last week with his son Tim, and they were planning several Lewis and Clark-related stops in Iowa and South Dakota.

"I would have loved to have gone in and gotten more information," Bergt said. "It is too bad they didn't start earlier or plan better."