Afghan National Army soldiers eat a meal in their barracks at Combat Outpost Monti in Kunar province. (TAUSEEF MUSTAFA/AFP/Getty Images)

As coalition forces withdraw from Afghanistan, U.S.-funded reconstruction projects worth billions of dollars in far-flung regions of the country will soon be impossible for American officials to safely visit and directly inspect.

The planned removal of more than 40,000 troops and the closure of dozens of bases over the next year will shrink the protective umbrella for U.S. officials to keep tabs on construction work, training programs and other initiatives in the corruption-plagued nation. Only about 20 percent of the country will be accessible to U.S. civilian oversight personnel in 2014, according to an analysis conducted by the special inspector general for Afghanistan reconstruction and obtained by The Washington Post.

Instead of curtailing those projects, the Pentagon, the State Department and the U.S. Agency for International Development plan to rely on teams of private contractors to monitor the work of other private contractors on the taxpayer-funded projects. In a document soliciting firms to help with inspections, USAID said it also intends to use satellite photos and “crowdsourcing” experiments that will solicit feedback on progress from Afghans who are supposed to benefit from U.S.-financed work.

The inability of U.S. government personnel to inspect development projects is prompting worry among lawmakers and government inspectors that millions more dollars could be squandered in what has become the costliest reconstruction of a single country in American history.

“I would be shocked if this doesn’t have an unhappy ending,” said Sen. Claire McCaskill (D-Mo.), who has been critical of reconstruction programs in Afghanistan and Iraq. “They are kissing oversight goodbye.”

U.S. government overseers will lose much of their access to large, government-funded projects in Afghanistan.

By plotting some of the largest civilian and military projects on a map generated by the inspector general’s office, The Post found that at least 15 major reconstruction initiatives, projected to cost more than $1 billion, are expected to be beyond the reach of U.S. government personnel next year. Among them are two of the U.S. government’s signature development endeavors: the $75 million installation of a new turbine at a dam in the southwest and part of the area where a $230 million highway is being built in the east.

The U.S. Army Corps of Engineers is building three garrisons for the Afghan army — each costing between $60 million and $80 million — in parts of the country that are outside the sectors identified by the inspector general as accessible.

“Many of these projects will never be seen by an American government employee, and that’s a concern,” said John F. Sopko, the special inspector general. “We need to ensure that tax dollars for these programs are properly spent.”

On-site monitoring by State, USAID and the Pentagon, as well as audits by inspectors general, led to dozens of projects being redesigned or scaled back over the past few years.

The ability of civilian government officials and military personnel to visit projects depends on the proximity of troops to respond to an attack — and on the ability of medical personnel to transport the wounded to coalition hospitals within an hour. As U.S. troops pull back to a handful of bases next year, travel will be circumscribed to areas within the radius of a 30-minute helicopter flight from those facilities.

Those areas almost certainly will shrink further by the end of next year. President Obama has not yet decided how many troops, if any, he will keep in Afghanistan in 2015 and beyond — he is waiting for the Afghan government to approve a security agreement with the United States — but even under the Pentagon’s most optimistic scenarios, the remaining U.S. forces would be clustered in just four or five bases.

The largest part of the reconstruction effort involves training and equipping Afghan security forces, a task that is expected to cost about $4 billion next year — the exact figure is awaiting congressional approval — and almost as much in following years. Over the past several years, U.S. military officers have been able to assess whether funds provided in Kabul, the capital, for salaries, fuel and equipment filtered down to troops on the front lines because American battalions often operated in partnership with Afghan ones.

With fewer troops in the field, the Pentagon is planning to increase the number of civilian advisers assigned to the defense and interior ministries. Those advisers will work with the Afghans to create new systems to track military property and other items paid for by the United States, a senior U.S. defense official said.

“The goal is to install a method of accountability,” said the official, who spoke on the condition of anonymity because the Pentagon has not yet provided a formal response to queries on the subject posed by Sopko.

The official also said the Pentagon would seek to place more responsibility on the Afghan government to track the use of U.S. funds. “We’ve told them that it’s incumbent on them to be good stewards of the resources given to them,” the official said.

A senior USAID official said the agency is confident that it can adequately monitor its work without U.S. military protection. “This isn’t anything new for USAID,” said the official, who spoke on the condition of anonymity because he was not authorized to speak on the record. “Most of AID’s work is done in the absence of a military presence.”

The agency is seeking to hire firms to design and implement a program to inspect reconstruction projects across the country. It anticipates spending $200 million on the effort.

“As the military draws down and our field presence diminishes, USAID will lose most, if not all, of its field staff . . . and experience drastically reduced mobility around Afghanistan,” the agency wrote in a contracting solicitation. “This constraint limits USAID officials from adequately monitoring program activities as they are occurring in the field.”

USAID is looking to hire contractors who can send Afghans with engineering and program-monitoring skills into areas beyond the reach of U.S. medical evacuation flights to collect information on development projects, including photographs with time stamps and precise geographic coordinates. The agency also is seeking to have the contractors create “monitoring tasks that the general public can objectively perform — commonly referred to as ‘crowd-sourcing.’ ”

The USAID official said the agency intends to use other methods, including video-conferences with construction teams and satellite photographs, to corroborate the work performed by the contractors. “We intend to rely on a multiplicity of layered approaches,” the official said.

The U.S. Army Corps of Engineers also said it plans to use contractors to monitor inaccessible projects.

But others involved in Afghan reconstruction voiced skepticism that satellite imagery and field reports from Afghans hired by a private contractor would be sufficient. “It’s difficult even for Afghans to inspect some of these projects,” said a U.S. reconstruction specialist. “If they’re walking around with a camera and a notebook, they’ll draw attention to themselves as someone connected with Western money.”

In a July report to Congress, Sopko, the inspector general, said his office is concerned that third-party monitors “may raise new issues such as vetting, accuracy, effectiveness, and accountability.”

Among those most affected by the travel restrictions will be Sopko and his auditors, who may not be able to conduct field inspections that can be used to sanction contractors or pursue criminal prosecutions. In a letter he sent this month to Defense Secretary Chuck Hagel and Secretary of State John F. Kerry, Sopko noted that earlier this year, his inspectors were unable to visit infrastructure projects in northern Afghanistan valued at $72 million “because they are located in areas that could not be reached by U.S. civilian employees.”

“Sopko is in a very difficult position,” McCaskill said. His auditors “can’t do their job adequately if they can’t be on the ground.”

Steven Rich and Jessica Schulberg contributed to this report.