MONTAGUE -- The High Point Monument is not falling apart, although bits and pieces of the granite spire's mortar are falling down so the area around the base of the 220-foot structure is taped off from visitors.

MONTAGUE -- The High Point Monument is not falling apart, although bits and pieces of the granite spire's mortar are falling down so the area around the base of the 220-foot structure is taped off from visitors.

The monument sits on the highest point (1,803 feet) in New Jersey and was completed in 1930. Rebecca Fitzgerald, superintendent of High Point State Park, said restoration of the monument was done in 2006. She has been at the park since 2010 and noted mortar fell the first winter she was there.

"We put barricades up when the first snow and ice arrive," she said about keeping people away from the base of the monument, mostly to prevent falls.

The process is known as "spalling" and is caused by the regular freeze and thaw cycles of winter where moisture gets into the mortar, then freezes and expands, causing cracks. As the cracks widen, more water can get in, expanding to the point that pieces of the mortar fall away.

Fitzgerald said that at least once a week, a park employee goes around the base of the monument looking for pieces of fallen mortar, which helps staff determine when to take away the barriers.

"It's been into July one year before we could take them down," she said.

Since the monument is atop a mountain, freezing weather lasts longer than at ground level.

Although the mortar does fall, there is no danger of the large New Hampshire granite blocks falling, she said. The blocks are held in place by their own weight, and the mortar is designed to keep snow, rain and moisture out of the joints.

Fitzgerald did say natural cracks were found and mapped during the 2006 renovations.

Future work will depend on costs and the amount of repointing of the joints to be done.

To erect scaffolding to do the work is "a substantial cost," she said.

The superintendent said she climbs the interior stairs every day during the season for her own visual check of the inside of the monument. The original design did not include an interior stairway and had thick glass at the openings at the top of the monument.

With restorations over the years, stairs were installed and a system to vent the interior was designed.

The interior of the monument is open to visitors from Memorial Day through Labor Day and on weekends into October.