Half a century ago, Pittsburgh's rivers and banks weren't the recreational attractions they are now. The banks were lined with scrap yards and salvage companies, warehouses and slag heaps. Mills dumped waste into the water along the banks. The water smelled bad. There were no inviting pathways along the river where people could walk or jog or bike as there are now.

"I remember cleaning the rails of the boat between every trip to keep the soot from building up," said Gateway Clipper Fleet president Terry Wirginis, who as a kid worked in the early days of his family's Gateway Clipper riverboat cruise business. "You could feel the grit on your fingers."

In the mid-'50s, then-Allegheny County Sanitary Authority treasurer John Connelly saw potential in the idea of recreational use of the rivers and believed an excursion boat could help to change the murky image of Pittsburgh's waterways. "He was one of the first ones who saw that these rivers were going to be different," says Mr. Wirginis, Mr. Connelly's grandson.

Mr. Connelly bought a Lake Erie fishing boat, which made its way to Pittsburgh via the Detroit River, Lake St. Clair, Lake Huron, the Straits of Mackinac, the Illinois and Mississippi rivers to the Ohio, landing here for its first cruise as the Gateway Clipper in May 1958. By the following year, the fleet added two more boats -- the Gateway Clipper II and the Good Ship Lollipop. Now there are five, all modeled after quaint riverboats and hosting a wide array of cruises.

Since 1958, more than 25 million passengers have taken Gateway Clipper cruises -- 700,000 of them in 2007. While Pittsburgh isn't a top tourist destination, the cruises draw former area residents who come back to visit and people who take visiting friends and relatives out for a day out the rivers, Mr. Wirginis said, along with corporate clients and charters. The Fleet also markets itself to a broad demographic range, offering dance and music cruises aimed at young people.

The draw, Mr. Wirginis said, is the chance to showcase the city from a vantage point no one else has. "I grew up in this town and on the river," Mr. Wirginis says. "You look at the difference in the last 10 years and it's amazing, but the difference in the last 50 years is beyond belief. When [former Pittsburgh mayor] David Lawrence started the renaissance, I don't think even he could have foreseen where we are today and how beautiful the city is."