Without press conferences, photo ops or fanfare, the prime piece of rebuilding at the World Trade Center site has reached major milestones in recent months: The National September 11 Mu­seum is now more than halfway to completion. The memorial park above it, among the most visible signs of progress on the 16-acre site, is more than 80 percent finished.

If work continues apace, the memorial and museum will open in 2011 and 2012, respectively. They will be the first finished projects at the World Trade Center site.

“There’s an energy down there now,” said Tom O’Connor, the Port Authority’s program director for the memorial and museum projects. “Everybody sees the light at the end of the tunnel, so everybody’s pressing for it.”

A tour of the site by the Trib in the heat of a cloudless June afternoon made that abundantly clear.

Throughout the 350,000-square-foot memorial plaza, tradesmen are at work, pouring concrete for its base slab in the southwest corner while teams in the northeast slather a finished portion of the base with steaming liquid rubber to prevent roots and water from penetrating the museum ceiling. Bricklayers near the western edge of the park are building some of the soil beds that will cradle approximately 400 swamp white oak and sweetgum trees, the first of which could be planted as early as September.

“That’ll be a nice sign that we’re getting close to the goal of bringing back some life to the site,” said Joe Daniels, president of the National September 11 Memorial & Museum.

Viewed from above, the most recognizable sign of progress at the memorial is the formation of the reflecting pools, marking the footprints of the Twin Towers and, since March, fully framed in steel. Inside each of the rectilinear craters, stone setters from the Port Morris Tile and Marble Corp. are installing the 350-pound granite panels that line the pools’ walls and floors.

According to Rich Gaviani, the foreman in charge of that crew, the job has been a formidable endeavor, both physically and emotionally.

“The first day I was here,” Gaviani said, “we were down in the lower level of the museum, and they had a mark on the floor that said, ‘0.0, North Tower.’ I was standing in the dead center of Tower 1, of where it used to be. That’s when I think we were all like, ‘Wow, this is what we’re doing.’”

Beneath the memorial plaza, hammers thunder against the bare steel and concrete walls of the nascent museum. Giant gleaming pumps are nested just below the bottom of the pools, awaiting connection to the pipes that will feed the waterfalls. Nearby, through a short maze of utility and mechanical rooms, what will become the museum’s imposing corridors and exhibition rooms are today as gray and coldly austere as an underground military bunker.

Later this year, crews will begin work on the above-ground entry pavilion, which will house two “trident” columns recovered from the northern façade of Tower 1.

Beneath the museum’s public halls, small tracts of soil still peek through the floor in a few unfinished corners of the superstructure’s lowest reaches, some 80 feet below street level.

Two iconic artifacts from the World Trade Center’s collapse—the Last Column, now encased in a hermetic seal, and the Survivors’ Staircase—already occupy their permanent spots in what will be the museum’s yawning main exhibition hall. In that same space, the rough surface of the Trade Center’s original slurry wall, which visitors will one day view from behind a rail, for now can still be touched.

Moving through the matrix of spaces that are to become the museum and memorial, their size and density conspire to skew one’s sense of scale. Squeezing through a tangle of steel rebar that protrudes from the floor, or climbing up a narrow scaffolding can unexpectedly lead to a trek across a long wide-open plain.

Surrounded by the everyday bits and pieces of a worksite—buckets full of shiny washers and bolts, coiled hoses and folded sawhorse, it is easy to lose sight of the enormity of these projects, or the emotional impact that awaits visitors in a little more than a year. But not so for those who work there daily.

“When you stand back and look at what you’ve done,” Gaviani said, standing at the bottom of the south reflecting pool, “you see something you’re going to tell your kids and grandkids about.”