Sixteen years after it was first eyed as a prime spot for Wegmans to plant stakes in the Philadelphia area, a onetime golf course near King of Prussia mall opened to the public this week as home to the latest regional megastore in the chain, whose customers share a cultlike devotion.

The parking lot at the Village at Valley Forge was jam-packed Monday, much as it had been when the store first opened Sunday, as hordes of the curious and the ravenous motored up to the 123,000-square-foot supermarket, visible from Route 422 and a stone's throw from the East Coast's largest shopping mall.

About 600 people have jobs there as a result of the Rochester, N.Y.-based grocer's decision to open in the highly trafficked zip code, a densely developed retail mecca.

Company officials were happy to celebrate the achievement, given that they had first expressed interest in placing a supermarket at that location in 1996. But the site of the former Valley Forge Golf Club became mired in litigation as its developer sought to change the zoning to permit a new use.

Assembling and developing the parcel had taken many more years than originally imagined by the now-deceased Wegmans family patriarch Bob Wegman, who had been told of the location at the urging of developer Dennis Maloomian.

Wegmans had not yet built a single store in Southeastern Pennsylvania when it set its sights on the King of Prussia parcel, spokeswoman Jo Natale said.

"It was a long, apparently arduous process for the developer," Natale said, and it was not until 2010 that the chain signed a lease for the project.

After a lengthy battle with Upper Merion Township that went to the Pennsylvania Supreme Court, and with the ultimate approval of township officials, Maloomian, president of Realen Properties in Berwyn, said Monday that Wegmans was the first sign of what will be a mixed-use development of housing, retail, and office space and medical facilities on the 132-acre parcel.

"The very first tenant prospect that we reached out to was Wegmans," Maloomian said, referring to his courting of the grocer back in the mid-1990s.

Although Wegmans built six other supermarkets across the region as Maloomian's project ground forward, the opening this week remained a point of pride.

Monday, the scene at the store was replete with imagery of a fruitful and eager clientele base: Shoppers luxuriated in ravishing displays of the chain's signature prepared foods, eclectic beers, a full-service restaurant, and the additional offerings of a conventional supermarket.

"I understand the madhouse, because with Wegmans they bring everything to the table," said Bryn Mawr insulation salesman and budding beer connoisseur John Lewis, 50, who finished his lunch hour inspecting the new store's selection of microbrews from this area and beyond.

Though already a customer at the Wegmans in Malvern, Lewis had been eager to take a break from his job in Valley Forge to see what was on tap and for sale by the six-pack at the new location. As he stood near a display of Goose Island Honker's Ale, he explained how he had ditched an effort to check out the store a day earlier.

He had been heading to a nearby Walmart on Sunday and thought he would swing by the new mega-market before heading home. But the Wegmans lot was jammed - so packed that police were directing traffic.

About 15,000 people turned out on Day 1, store manager Kevin Lang said, and an estimated 5,000 more had swung through by midday Monday.

From a customer's standpoint, Lewis said, the appeal is clear.

"They bring a vast selection of very desired items for an assortment of different customers," he said, articulating the business model that has turned Wegmans into a titan whose arrival in any community is downright magnetic.

The King of Prussia store is the only opening in the region this year, in accordance with a companywide philosophy of slow-but-sure development across the Northeast and mid-Atlantic. Wegmans opens no more than three a year, if that. A store at Montgomery Mall is tentatively scheduled to open in 2013, but no others have been announced.

Its first store in the Pennsylvania suburbs of Philadelphia opened in 2003 in Downingtown, followed by Warrington in 2006, Collegeville in 2009, and Malvern a year later.

All of those sites were chosen years after Wegmans family officials had pinned their hopes on securing a lease in King of Prussia, Natale said, and the protracted efforts to make the property developable ensued.

The nearest store is up Route 422 in Collegeville, a strikingly short distance, given the chain's footprint elsewhere in the region. Its only two stores in South Jersey, for instance, are in Cherry Hill and Mount Laurel.

Natale said the company is convinced that "in the Malvern-Collegeville-King of Prussia triangle, there are enough people living in those areas or traveling in those areas or working in those areas to make all three stores very successful."