A visiting group of masons is giving some needed TLC to the historic wall surrounding the Orchard Knob Reservation.

Over 100 years old, the gray cut-stone wall has a number of missing or broken capstones and needs new mortar in many places.

The crew, part of the National Park Service's Historic Preservation Training Center based in Frederick, Md., travels all over the country to preserve the nation's historic locations and monuments and are well-versed in the art of restoration.

"We go through all the proper steps to replace in kind the mortar and stones in the wall," said Petey Bender, the project specialist with HPTC. "We cleaned and power washed the whole wall, removed all failing mortar and joints and we're working on cutting and replacing capstones."

The key is maintaining the original look of the wall. Every stone cut and every blob of mortar tucked into a crevice is made to look as authentic as possible.

To accomplish this, the crew will be holding a training session later this month to study the wall's original capstones as they cut new ones. In addition, the group is using a Portland cement-based mortar, which they are texturing to blend in with the existing mortar.

The preservation work is expected to be completed by the end of March, just a few months before the Park Service gears up for its commemoration of the 150th anniversary of the Civil War battles that took place in and around Chattanooga.

Orchard Knob played a prominent role in those events. On the afternoon of Nov. 23, 1863, 634 Confederate sentries posted along the hill watched as 14,000 Union troops advanced.

"By the end of the day, Orchard Knob had fallen into Union hands," Jeffry Thul said in a news release from the Chickamauga and Chattanooga National Military Park. "On Nov. 25, Orchard Knob became General Ulysses S. Grant's forward observation post as he watched the Federal forces assault Missionary Ridge."

The federal government bought the land in 1893 and the wall, with crenelated entrance pillars and decorative iron gates, was completed in 1899.

While the crew completes preservation work, the areas immediately surrounding the wall will be closed to the public, Thul said.