The 4-H barn that was destroyed by a tornado last fall will not be rebuilt in time for tomorrow's opening of the 69th annual Loudoun County Fair. Instead, local youths will have to house and show their prize sheep, poultry, goats and rabbits in several tents during the weeklong livestock exhibition.

"It's going to be a little bit of a logistical problem, but we think we can cope with it," said Terry Corle, the fair's general manager.

Organizers say that although the tents might be cramped, no young competitors have been turned away because of a lack of space.

"We've done everything we could to accommodate all the kids that wanted to show," said Liz Shockley, treasurer of Loudoun County Fair & Associates, the board that manages the fairgrounds off Dry Mill Road in Leesburg.

More than 10,000 people are expected to attend this year, said Corle, who called the fair a significant educational experience in a rapidly developing area.

"Most young children nowadays have no idea where milk comes from or where a hamburger comes from. It's just 'from a store,' " said Corle, an insurance agent with the Loudoun County Farm Bureau. "Here, they can see crops, touch the animals and ask questions."

In addition to the traditional livestock judging and auction, activities at the fair, which runs tomorrow through Saturday, will include country music, a rodeo and the Miss Loudoun County pageant. New events this year will include a petting zoo and a gospel jamboree Tuesday, featuring the Skyline Boys and Signed Sealed and Delivered.

A tornado nearly leveled the 40-year-old 4-H barn Nov. 5. No one was hurt, and there were no animals inside at the time. But the wooden structure, actually a combination of three buildings, was damaged beyond repair. Most of the front section caved in, and debris was spread across much of the fairgrounds. Planks that splintered off the barn pierced a wooden fence, and part of the roof ended up on a nearby slope.

Local 4-H clubs and other members of the community raised $100,000 for a prefabricated barn, Corle said. During construction, however, costs crept from $250,000 to $300,000, in part because an old foundation had to be removed, delaying the project.

When the fair opens, only the steel skeleton of rafters and roof beams -- known as the "red iron" -- of the new barn will be in place. Some of the barn's side panels are on the ground nearby waiting to be installed, and other parts are in a storage trailer at the fairgrounds. Smaller wooden barns nearby, which were not damaged by the tornado, will house pigs and cattle during the fair.

Organizers said they hope that seeing the half-finished barn will inspire donations to the construction effort, which is expected to be completed in August.

In the meantime, local 4-H youth have been making final preparations for the big event: shearing their sheep and gathering their buckets, hoses and other supplies. Among them is Sarah Hatch, 17, who plans to exhibit a heifer and two lambs, one of which she hopes to sell at auction.

"This is the week that you show off your hard work, and people get to see what you've done for the past year," said Hatch, a rising senior at Loudoun County High School in Leesburg.

Every day this week, she and her friends will be at the fair by 5:30 a.m. to feed and groom their animals and will probably stay until 8 p.m. or later helping with each other's livestock.

Hatch said she was disappointed that the barn would not be ready but looked forward to the annual festivities. "Just being at the fair is a whole bunch of fun," she said.

The Loudoun County Fair is held at the Loudoun County Fairgrounds, 17564 Dry Mill Rd., Leesburg. Hours are 5 to 10 p.m. tomorrow and 9 a.m. to 11 p.m. Tuesday though Saturday. A weekly pass is $15 for adults, $7 for ages 6-12, and free for 5 and younger. A daily pass is $7 for adults, $4 for ages 6-12, and free for 5 and younger. 703-777-3835.

The new 4-H barn at the fairgrounds is expected to be completed in August.