NAUVOO, Ill. -- For Sale signs dot the landscape of this town on the Mississippi River -- offering not only Mormon pioneer homes but 1950s ramblers, pizza parlors and an abandoned building to the highest bidder.

That buyer is usually a member of The Church of Jesus Christ of Latter-day Saints.

The opening of the Nauvoo Temple, which is rising again from these bluffs some 140 years after the original was destroyed, is drawing droves of Mormons -- a growing number to stay, many to visit.

And that has not a few residents alarmed that the influx will forever change the Nauvoo they know.

At the same time, many in this town of 1,100 or so are ready to capitalize on the newcomers and the 350,000 tourists expected to visit over the next two months -- about 100,000 more visitors than Nauvoo typically receives in an entire year.

For most visitors and newcomers, it's a nostalgic return to their faith's roots. Mormons built this tidy town on a swamp in 1839 -- only to be driven out of their homes by angry neighbors a mere seven years later. A few stalwarts stayed behind to finish the original temple, only to have it ravaged in an arson fire and, later, demolished by a tornado.

The LDS Church announced plans in 1999 to rebuild the temple, recapturing the historical import of this place.

Mormons make up only 10 percent of Nauvoo's population and, by the LDS Church's count, there are about 13,000 members in the new temple's district.

But Nauvoo is where LDS Church founder Joseph Smith announced many revelations that became cornerstones of the faith. He was killed in 1844 in nearby Carthage, Ill. And it is from here that Brigham Young led the Mormons west to Utah.

Today, Nauvoo is every bit the portrait of small-town America. Its main street -- Mulholland Road -- is about five blocks long with one fast-food restaurant, a single convenience store/gas station, a couple of taverns, a grocery store, some antique stores and two restaurants -- Dolly's and Grandpa John's.

The new temple, which opens for public tours on Monday, sits on a bluff at one end of Mulholland Road, overlooking what locals call "The Flats" -- the historic district that features a number of restored Mormon pioneer homes. The town today is surrounded by farmland and grassy vacant lots -- but that bucolic setting appears destined to change.

A land rush began in Nauvoo almost immediately after the rebuilding project was announced. Housing and land prices skyrocketed. Among the newcomers were workers hired to help construct the temple. Now, Mormon retirees are being drawn to Nauvoo.

"There are more homes for sale than ever before in my memory," says Wayne Marting, owner of Marting Real Estate. "Seventy-five to 80 percent of the recent sales have been to Mormons."

It all began, says tourism director Joseph Johnstun, when a house in The Flats sold for $200,000 -- tripling its previous market value. That spawned a house-selling frenzy, driving property values through the roof.

"I get at least three people a day asking me to put up a notice about their home for sale in our window," says Johnstun, who always declines.

And that's just one way residents are cashing in and putting entrepreneurial talents to work.

Arlo Sinele, a Nauvoo pilot affectionately dubbed "the fly guy," bought a roll of film at Wal-Mart in a nearby town for $5 and took some aerial shots of the temple during its construction. Now he is selling them through the LDS Church-owned publishing house, Deseret Book.

David McManus has produced stereoscope postcards of such items as the sunstone, one of the temple's most notable architectural features, which he offers at $7.50.

Hotel and motel owners are expecting business to boom during May and June. McManus' own River Spirit Hilltop House has only seven vacancies left through the end of June.

"It's Mormon gold fever," Johnstun says.

While they capitalize on their town's unique history, locals are worried. Some fear Nauvoo is being transformed into a largely LDS community, just as it was in the 19th century. Even those who don't plan to stay can leave a distasteful imprint.

Every year a dozen or more Mormon tourists come to town and treat everyone who lives here "as if they were a descendent of the mob [that killed Smith]," says Johnstun, himself a Mormon. "They act as if Nauvoo is their birthright."

Joan Kraft, who owns a home just off Mulholland Road built in the 1840s, often finds strangers trampling on her lawn and peering in the windows. When confronted, the tourists justify their actions by saying an ancestor once lived there.

Such insensitivity -- and the crush of visitors expected -- may have been what prompted LDS Church President Gordon B. Hinckley to issue an unusual appeal last week for courtesy on the part of Mormon tourists during the two-month open house.