The letters typically spoke to the anguish of not knowing, of the long, wretched vigil of wondering if, by some miracle, the writer’s son had been spared. In September of 1866 a grieving mother, Mrs. T. B. Hurlbut, from Upper Alton, Illinois, penned a desperate letter to Barton’s office. “I approach you with my great sorrow,” she wrote, “but hardly indulge the hope that you can do anything for me. My darling boy, my only son, was reported killed. . . . His body was not found, and the hope was entertained by his Regiment . . . that wounded he had fallen into the hands of the enemy, a prisoner and not dead. ... If he died on the battle field, I would that I knew it, and if he died at a farm house, how much I wish to know it. ... It may be well to add my son’s name to the many missing ones, and could you by any means give to me any knowledge of the last resting place of my darling one you would confer such a favor as none less desolate than myself can appreciate.–

Clara Barton was moved enough to keep Mrs. Hurlbut’s letter in a special envelope she titled “Scraps for My Book,” though most likely the poignant appeal elicited the form letter that the sheer volume of correspondence had forced Barton to compose: “Dear [recipient’s name], Your communication of [date] is received and the name of [missing soldier] placed upon my lists. It will be my earnest endeavor to bring these lists to the notice of returned soldiers everywhere. Be assured that as soon as any information of interest to you is gained, it will be promptly forwarded. Very sincerely yours, Clara Barton.”

Barton’s printed circulars of the missing had a distribution nearing 100,000. That a woman and a civilian planted the roots for what is today a $104 million operation through the U.S. Department of Defense to find and repatriate U.S. soldiers from half a dozen wars is remarkable. That her own little office would itself meet with the same fate as that of the soldiers she worked so tirelessly to find is, perhaps, more remarkable still.

This is Augustus Goodman’s first mission to the A Shau Valley in Vietnam, but the second for JPAC in as many years looking for this warrant officer. So far, along with viper, worm, coral, and cobra snakes, land and water leeches, stinging ants, and biting centipedes, they have found a rusted M-16 bayonet, what is possibly a whip antenna from a radio, a load-bearing equipment fastener typically used to attach items to a soldier’s belt, myriad burnt metal and plastic pieces, spent shell casings, and an unused .45-caliber round of the sort carried by pilots. Perhaps the most telling evidence found so far is the data plate off the plane, a tiny piece of metal that lists the serial number, make, and model of an aircraft and which can be correlated exactly to the 1967 helicopter that went down.

The previous mission found a compass, a survival knife, and a boot, along with a scattering of Plexiglas globules formed when the helicopter’s windshield melted. None of it is enough to classify our warrant officer on its own. The military’s standards for identifying a soldier are exacting; dog tags alone are not enough, nor is a data plate, or personal effects like boots, helmets, and wedding rings. Not even a bit of bone is enough. But all these items, in various combinations, establish an identity.

The dig is set up like an archeologist’s site, using block excavation in four-by-four squares measuring 9,100 square feet. Once location is established through military records, historical research, and on-site investigations, which include witness interviews, a team like Goodman’s will set up shop for a four- to six-week stay. Though teams often put up in nearby guesthouses or hotels, the A Shau Valley is so remote that the team first must build a tented base camp where they will eat, sleep, and shower. The dig is a half-mile trek from this camp, along an up-hill, downhill, uphill path over trampled leaves and honey-colored mud. It has rained for nearly 12 hours straight, and the ground is like an oil slick. The 100 villagers hired to work this site walk an hour or two in flip-flops each way to get to the digging area from Houng Phong, their village.

The dig takes place on a treacherous slope leading to a steep ravine full of white-veined rocks and shallow trees in an area that would have been classified just a few weeks ago as a double-canopy jungle but which has since been cleared. (For every tree that is cut down, the U.S. government reimburses Vietnam, which theoretically uses the money to re-forest.) The grids are measured above-ground and dug out anywhere from a couple of centimeters to several feet, depending on the crash site and the terrain. The task is essentially to dig until “sterile” (undisturbed) ground is reached and then to move to a new location. Buckets of earth are filled and handed down a line of dozens of Vietnamese and sent to the covered screening station, where the dirt is dumped onto screens and sifted for clues. “Anything not of the earth” is the mantra for choosing what to look for.