Covered beauties

First-time visitors to the Bull Run restaurant and nightclub in Shirley often do a double take when they veer off Route 2A and head around back looking for a place to park. Tucked behind the building and connecting two sections of the parking lot is a large, austere, wooden, and very functional covered bridge.

The unpainted structure spans Mulpus Brook, a tributary to the Nashua River. With its peaked roof and lattice sides, the bridge is an attractive and sturdy work of craftsmanship. But it is not historic.

"My father-in-law built it in 1971 to connect the parking lot," said Dolores Guercio, who with her husband, Chip Guercio, runs the restaurant. "It was part of the expansion of the restaurant back then."

Covered bridges are icons of early rural America, evoking a time before the invention of steel and concrete. These simple landmarks - built with barn-like roofs to protect the wooden timbers below - typically span picturesque streams. Covered bridges that were built in the 19th or early 20th centuries are an endangered species. There are only about 1,000 nationwide, and many of those are vulnerable to fire, vandalism, flooding, and neglect. Old covered bridges are highly valued by historic preservationists, and societies have been formed all over the country to save them.

In a murkier category, though, are modern covered bridges - like the one behind the Bull Run - built for aesthetics, nostalgia, and, sometimes, even practicality.

"People build them for whatever reason," said Dale J. Travis of Decatur, Ill., who runs a website on covered bridges. "Sometimes they're not even built over anything."

In the suburbs northwest of Boston, in both Massachusetts and New Hampshire, no historic covered bridges have survived into the 21st century.

But the region does have a handful of covered bridges built in recent decades, carrying both pedestrians and vehicles.

They include Pepperell's downtown covered bridge, heavily used but in need of repair. At the Wayfarer Inn in Bedford, N.H., there is a covered footbridge that links the hotel and convention center. Kimball Farm in Westford has a prominent covered footbridge at the entrance to the miniature golf course next to the bumper boats.

On Stowell Road in Merrimack, N.H., near a modern subdivision is a decidedly nontraditional covered bridge, built across Baboosic Brook in 1990. The town constructed the wooden bridge with an asphalt deck after determining that a noncovered concrete structure would have been more expensive.

Tom Lowry, a retiree in Mannasas, Va., said he has a fondness for covered bridges old and new. He runs a covered bridge website with many pictures of Massachusetts and New Hampshire bridges.

"I have no problem with a nonauthentic bridge," said Lowry. "If it's got a cover on it, I'll take a picture of it."

The craftsmanship that goes into covered bridges makes all of them special, according to Lowry. "They are hand built, even the new ones. As far as I know, no one has a factory to put these puppies up," he said.

Susan B. Kominz, a photojournalist from Campton, N.H., said historic covered bridges are most important to preserve, but newer ones also have value.

"I would not look down on someone who builds a covered bridge today in an old style or a more modern one. Virtually anything that gets people interested in the history is a good thing," she said.

But other covered bridge enthusiasts do not feel as kindly to the newer structures.

"I'm not a big fan of them," said David W. Wright, president of the National Society for the Preservation of Covered Bridges and a resident of Westminster, Vt. "It's like artificial maple syrup vs. real maple syrup."

Wright, however, does prefer a new covered bridge to the soulless overpasses used in most of the country.

"Even the newer ones, which are homelier than the ones of the 19th and early 20th centuries, are better to look at than a steel and concrete one on a highway," he said.

The bridge behind the Bull Run is much used and much admired. Visitors often linger on their way to the restaurant on the side of the bridge with a separated pedestrian walkway. Weddings have been held on the bridge. In 2001, the National Society for the Preservation of Covered Bridges held its annual meeting at the Bull Run.

The bridge was built to evoke an earlier time, according to Dolores Guercio.

While the bridge is not historic, the restaurant, or a section of it, is. "Part of the restaurant dates back to 1740. They just thought it was appropriate to make the bridge from that era," she said.

Mike Kimball, owner of Kimball Farm, said his covered bridge will last a lot longer than an uncovered bridge, but that is not the reason he built it.

"It's more for the aesthetics," said Kimball. "The original plan was for a walkway, but we decided to cover it."

He said he does get inquiries about the bridge. "On all of our buildings, we get a lot of people asking questions," he said.

The Wayfarer Inn's covered bridge, built in 1963, is a highly functional, modern walkway over a stream. Royal Crest Estates, an apartment complex in Nashua, has a covered footbridge near its entrance.

Pepperell's Chester Waterous Covered Bridge over the Nashua River was built in 1962, replacing an original covered bridge erected in 1848.

The state is planning a major reconstruction of the bridge, which has retained as decoration some of the wood from the original structure.

One of the more unusual covered bridges in the region is in Brookline, N.H. In 2001, an arts and crafts shop in Nashua donated the bridge to the town, which installed it over the Nissitissit River, where a railroad bridge once stood.

Covered bridges were once known as "kissing bridges" because of the seclusion they provided for lovers looking to steal a kiss.

Last year, the Nissitissit footbridge parlayed that reputation into a bit of fame when Cosmopolitan magazine put it on a list of sexiest spots in the country and labeled it New Hampshire's "loveliest kissing bridge."

Robert Preer can be reached at preer@globe.com.