U.S. President Donald Trump threatened on Wednesday, September 9, to escalate the Iran war further by attacking the Pickaxe Mountain complex — an Iranian nuclear site buried deep underground and currently beyond the reach of known U.S. military technology.
New reports suggest the Pentagon is investigating classified ways of destroying the underground facilities.
OVER NEVADA — A B-1B Lancer from the 37th Bomb Squadron, Ellsworth Air Force Base, S.D., streaks through the sky. Carrying the largest payload of both guided and unguided weapons in the Air Force inventory, the multi-mission Lancer is the backbone of America’s long-range bomber force. It can rapidly deliver massive quantities of precision and non-precision weapons against any adversary, anywhere in the world, at any time. (U.S. Air Force photo by Master Sgt. Lance Cheung)
A U.S. Air Force B-1B Lancer flies in the U.S. Central Command area of operations, Oct. 25, 2019. The bomber flew directly from its home station of Ellsworth Air Force Base, S.D., demonstrating the U.S. Air Force’s ability to rapidly deploy strategic bombers anywhere in the world. U.S. Strategic Command regularly tests and evaluates the readiness of strategic assets to ensure we are able to honor our security commitments. (U.S. Air Force photo by Master Sgt. Joshua L. DeMotts)
Speaking at the Republican midterm convention in Dallas, the president said that U.S. intelligence has detected “a little activity” at the Pickaxe site.
“I would advise Iran not to get cute because we will have to hit them very hard,” he said.
The comments come after new satellite analysis has shown that Iran has carried out more construction activity at Pickaxe Mountain this year than at any other time since analysts began tracking the site.
And they come after the Pentagon began preparing for a classified live-fire experiment at a subterranean test facility in New Mexico.
Speaking to CNN, sources familiar with the tests said that the test was connected to the Iran war.
Pickaxe Mountain, known as Kuh-e Kolang Gaz La in Farsi, is a tunnel complex roughly two kilometers south of Iran’s damaged Natanz nuclear facility in Isfahan Province.
The facility is buried beneath granite and is suspected of being intended to house sensitive parts of Iran’s nuclear program, thereby allowing Iran to rebuild the program safely in the knowledge that U.S. bunker-busting bombs cannot reach it.
What Satellite Images Show
A new analysis of satellite imagery by the Center for Strategic and International Studies (CSIS), published on Wednesday, showed a significant change in Iranian activity at the site in 2026 compared with the last six years.
Researchers say that they found more road activity around Pickaxe this year than at any previous point in the site’s history, with Iran hardening tunnel entrances and paving internal roads.
The researchers also noted that access areas had been reinforced and materials excavated from inside the mountain had been removed or flattened.
Iran might also be moving beyond simply digging tunnels and could be preparing to use the site for nuclear development purposes.
The researchers also said that work to reinforce exterior entrances is still underway.
What the analysis does not do, however, is establish that uranium enrichment is actively taking place at the site.
That, in fact, is extremely unlikely.
The absence of some equipment and security activity normally associated with an operational enrichment facility suggests preparations are still underway ahead of the site becoming operational, but it remains unclear exactly what Iran has in mind for the site, which international nuclear authorities have never inspected.
“Together, these images reveal more road activity at Pickaxe Mountain in 2026 than at any point in the site’s history.
There is a clear surge in construction activity in 2026 that corresponds to the raising and hardening of the portal accesses, paving of the internal road network, reinforcement around access areas, and the flattening and removal of excavation spoil,” the new assessment reads.
The U.S. Can’t Currently Reach It
Pickaxe Mountain has not been targeted by recent U.S. and Israeli operations — not because it is an unimportant site, but because Washington and the Pentagon cannot be certain that even its most powerful conventional bombs can destroy it.
To destroy Pickaxe Mountain would require explosive power that penetrates far deeper into rock than current bunker-busting bomb technology can.
The site, after all, is protected by a substantial amount of granite, with its deepest sections likely beyond the reach of the 30,000-pound GBU-57 Massive Ordnance Penetrator (MOP) that was used during Operation Midnight Hammer.
Some estimates put elements of the Pickaxe Mountain site at around 170 meters deep.
But the U.S. may be preparing new methods to reach that deep underground — and President Donald Trump continues to tease the possibility of launching an attack on the site.
Pentagon Prepared Secret Test
A CNN report from September 9 described how the Pentagon may be preparing new technology capable of reaching deeper targets, noting that the Defense Threat Reduction Agency had authorized emergency preparations for a classified live-fire experiment at White Sands Missile Range in New Mexico shortly before the war with Iran began.
The report suggests, then, that Washington anticipated that targeting the site may become critical at some point in the conflict.
Federal contracting records appear to show around $1.2 million in funding for urgent work at the Alternate Seismic Hardrock in Situ Test Site – an underground facility carved into granite and designed for testing how weapons fare against deeply buried targets.
It’s exactly the kind of site that the United States would need to test weapons intended to take out a target buried deep inside Pickaxe Mountain.
Satellite imagery showed excavation beginning at the site in February and continuing into March.
Three sources familiar with the project told CNN that the planned experiment was connected to the Iran war, although the network could not establish whether the classified test ultimately occurred.
What’s more, the Air Force is currently developing a “Next Generation Penetrator” to succeed the GBU-57, and a prototype development contract for the new weapon was awarded in September 2025.
The U.S., it seems, may be preparing to take out Pickaxe Mountain — but if the technology were ready, the strike may have occurred by now.
About the Author: Jack Buckby
Jack Buckby is a British researcher and analyst specializing in defense and national security, based in New York. His work focuses on military capability, procurement, and strategic competition, producing and editing analysis for policy and defense audiences. He brings extensive editorial experience, with a career output spanning over 1,000 articles at 19FortyFive and National Security Journal, and has previously authored books and papers on extremism and deradicalization.
