The Day the U.S. Army Went to War with the Susquehanna River

During the winter of 1919–1920, the Susquehanna stopped behaving like a river.

It did not roar or surge or spill its banks. It went eerily still. For eighty-three days, it lay frozen from shore to shore, a hard white lid pressed down over moving water, silent enough that people could walk across it and forget—briefly—that a river was supposed to move.

By early March, that stillness had become ominous. The ice that had formed in December had not thinned or retreated. It had thickened. Locked together, layer upon layer, it stretched unbroken through the lower reaches of the river near Port Deposit, turning a living waterway into something closer to stone.

When the thaw finally came, it did not come gently. The warming air loosened the surface, and rain and snowmelt from far upstream pushed southward, pressing against the frozen mass. The ice fractured, but it did not clear. It broke into slabs and plates that surged forward only to wedge themselves tighter at bends, islands, and bridge piers. The Susquehanna did what rivers do when restrained. It pushed back. Water piled behind the ice gorge, climbing higher by the hour, creeping toward streets and storefronts, threatening to spill into the town below.

The people of Port Deposit had lived with ice all their lives. They knew its sounds, its moods, the way it groaned at night and cracked at dawn. Ice had once been a resource, harvested in winter and stored for warmer months. But this was different. This was ice turned barricade—an unstable dam made of the river’s own broken pieces.

Ice jam flooding was not like ordinary flooding. In a typical flood, water rose and spilled outward, soaking cellars and filling streets before eventually receding. An ice jam added weight and motion. When the gorge failed, it did not simply release water; it released thousands of tons of moving ice, acting like battering rams. Blocks large enough to shear hundred-year-old trees could crush buildings as if they were made of cardboard. They could tear loose docks, splinter bridge piers, and grind their way through anything caught in their path.

Port Deposit’s vulnerability was well known long before 1920. The town sat tight to the river, and the lower Susquehanna’s geography, with its bridges, islands, and narrowing reaches near the river’s mouth, made it a natural trap for moving ice. When a gorge formed here, it did not drift through. It held. And when it broke, it broke violently.

No one could get close enough to cut it. The surface was too unstable, the pressure beneath too great. There were bridges and rail lines to protect, and no time left for cautious solutions. Someone made a call.

Not to engineers with saws or crews with cables, but to a place built for experiments and explosives. Aberdeen Proving Ground lay only a short distance away, and in the winter of 1920, it held something few river towns had ever seen overhead: airplanes.

On March 9, residents along the lower Susquehanna looked up to see a biplane circling above the ice. The aircraft dipped and climbed, its engine echoing off the frozen surface below. Then it dove. The bomb fell cleanly into the gorge.

Witnesses would later describe the blast not as a sharp crack but as a deep, muffled roar. It was followed by the sudden eruption of water, ice, and mud thrown skyward. A hole hundreds of feet across was torn out of the frozen mass. Where there had been a white plain moments before, there was now churning black water. Wild fowl erupted into the air all at once, the sky briefly darkened by startled wings. The concussion rolled outward along the river corridor, felt by men working downstream and by watchmen stationed high in bridge towers.

Nearby, a passenger train crossed the Baltimore & Ohio Susquehanna Railroad Bridge at the moment of detonation. Those inside likely felt the vibration before they understood what they were seeing: a war-era airplane attacking the river beneath them, turning the Susquehanna into a target.

The pilot was Lt. Rene Studler, flying out of Aberdeen in a De Havilland DH-4 bombing plane. He would make repeated seventeen-minute runs, looping back and forth between the proving ground and the river, dropping explosives into the gorge to open a channel and relieve the pressure building behind the ice. Crowds gathered to watch. Airplanes were still a novelty in 1920; seeing one dive on a frozen river and detonate it from above was something else entirely. It was part emergency response, part public spectacle, and part experiment unfolding in real time.

The first blasts, using 112-pound bombs, shattered the ice, but the river resisted. Broken slabs drifted only to jam again downstream, stacking against islands and bridge piers as stubbornly as before. The gorge fractured, shifted, and locked again. Larger bombs were brought in—first 230-pound charges, then 250-pound bombs. More runs were flown. The situation grew increasingly dire, and finally, the Army brought out the heavy hitters: 500-pound TNT bombs. In total, more than 5,000 pounds of explosives were dropped into the frozen river over the course of two days, weakening the mass, breaking it apart, but not yet freeing it.

Regional newspapers from Lancaster to Baltimore were filled with headlines that read like battlefield dispatches, such as “Bombs break up ice gorges in Susquehanna” and “Army fliers shatter Susquehanna Gorges with big TNT bombs.”

For a time, it looked as though the Susquehanna might win the battle.

Then, on March 12, something changed. The ice began to move—not all at once, but enough to be noticed first in the channel. There was a grinding sound, low and sustained, as if something enormous were tearing itself loose. The gorge buckled. The mass gave way. Ice that had been locked in place since December began to slide downstream, breaking apart as it went, grinding against itself and the riverbanks, moving steadily toward the bay.

By afternoon, the river below Port Deposit was clear for the first time in months. The threat eased. Water levels dropped. What remained of the ice continued its slow, destructive journey out into open water, leaving behind a river that once again behaved like a river.

It was never entirely clear where to assign credit. The bombing had weakened the gorge, fractured it, riddled it with hidden fault lines. The moderating weather had softened the ice. Together, they had done what neither might have accomplished alone. The newspapers said as much, careful not to claim too much victory for any single force.

What remained undeniable was this: for several days in March 1920, the Susquehanna had been treated like an entrenched enemy. A frozen river had drawn aircraft, explosives, and the full confidence of a postwar nation convinced that modern tools could solve even ancient problems. And for a moment—just long enough to save Port Deposit—it worked.

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Resources

• The Evening Sun Tue, Mar 09, 1920 ·Page 1
• The Baltimore Sun Wed, Mar 10, 1920 ·Page 3
• The Evening Sun Fri, Mar 12, 1920 ·Page 1
• Lancaster Examiner Sat, Mar 13, 1920 ·Page 8
• York’s Past: Aerial bombing breaks Susquehanna ice jams
• The day they bombed the Susquehanna
• Aerial bombing breaks Susquehanna ice jams
• River Roots: Ice Jams on the Susquehanna
• De Havilland DH-4

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