The last American soldier left here Wednesday, abandoning a base surrounded by tall cedar trees and high mountains, in a place that came to be called the Valley of Death. The near daily battles here were won, but almost always at the cost of wounded or dead. There were never enough soldiers to crush the insurgency, and after four years, it became clear that there was not much worth winning in this sparsely populated valley. Closing Korengal Outpost in Kunar Province, a powerful symbol of some of the Afghan war's most ferocious fights, and a potential harbinger of America's retreat, is a tacit admission that putting the base there in the first place was a costly mistake. It is also part of an effort by Gen. Stanley A. McChrystal, commander of forces here since last summer, to consolidate and refocus forces where they might change the momentum of what had become a losing contest. Fighting for isolated mountain valleys like this one, even if they are hide-outs for clusters of Taliban, was no longer sustainable. It did more to spawn insurgents than defeat them. Better to put those soldiers in cities and towns where they could protect people and help them connect to the Afghan government, he reasoned. 'There's never a perfect answer,' McChrystal said as he visited this outpost on April 8 for a briefing as the withdrawal began. 'I care deeply about everybody who has been hurt here, but I can't do anything about it. I can do something about people who might be hurt in the future. 'The battle changes, the war changes,' he added. 'If you don't understand the dynamics, you have no chance of getting it right. We've been slower here than I would have liked.' Forty-two Americans died fighting in the Korengal Valley and hundreds were wounded, according to the military. Most died in the period from 2006 to 2009. Many Afghan soldiers died as well, and in larger numbers, since they had poorer equipment. In a war characterized by small, brutal battles, the Korengal had more than its share, and its abandonment has left soldiers who fought there confronting confusion, anger and pain. 'It hurts,' said Spc. Robert Soto of Company B, First Battalion, 26th Infantry, who spent 12 months in the valley from 2008 to 2009. 'It hurts on a level that -- three units from the Army, we all did what we did up there. And we all lost men. We all sacrificed. I was 18 years old when I got there. I really would not have expected to go through what we went through at that age.' During the period Soto served there half of his platoon was wounded or killed, according to the unit's commanding officer. 'It confuses me, why it took so long for them to realize that we weren't making progress up there,' Soto said. Korengal Outpost was the third area of eastern Afghanistan where combat outposts closed: In 2007 and 2008 two posts and a smaller satellite base were closed in the Waygal Valley of Nuristan Province; in 2009 two posts were closed in the Kamdesh region of Nuristan. Along with the main Korengal outpost, five satellite bases closed; at least two, Restrepo and Vimoto, were named for soldiers who died there. Perched on a steep hillside sprinkled with gnarled trees, Korengal Outpost is little more than a dozen structures made of stone and wood and is heavily sandbagged. It is a primitive-looking place built into the hillside, like the nearby villages. Farther down the valley tower the deodar cedars that the Korengalis cut down to make their living. The vulnerability of these combat outposts was hardly surprising. Though sparsely populated, Kunar and Nuristan provinces have a long history of strident resistance to outsiders. Kunar was one of the first places to rise up against the Soviet occupation in the 1980s, giving the area the label of 'cradle of jihad.' Much of the U.S. mission in the last couple of years has been to try to get the reclusive people who live here to recognize the Afghan government and work with it. In some places that approach is reaping modest results. Not so in the Korengal. The Korengalis speak a language unrelated to Pashto or Dari, the two main Afghan tongues. They practice a conservative brand of Islam and have repeatedly rebuffed American offers of aid. The area remains under the influence of a Taliban shadow governor along with two Taliban leaders, Hajji Mateen and Nasrullah, who make their money from the valley's lumber. The sawmill and lumberyard run by Hajji Mateen was seized by Marines to build the Korengal outpost in April 2006. The troops had set out to penetrate the six-mile-long valley, but never made it more than halfway. There have been only two missions to the valley's southern end since 2005, said Maj. Ukiah Senti, the executive officer of Second Battalion, 12th Infantry Regiment, Task Force Lethal, which oversees Korengal and neighboring areas. He said the antagonism from local Taliban and insurgents was so great that it would have taken a battalion-size force to make a foray there. The Korengal Outpost was opened to root out Taliban fighters hiding deep in the mountains, according to soldiers who fought there. Even before then, it was apparent that the valley's inhabitants were hostile to outsiders. In June 2005 a four-man Navy SEALs team was ambushed on a ridge above the valley; three members were killed, and a helicopter sent to rescue them was shot down, killing eight more members of the SEALs and eight other servicemen. While there were Taliban in the valley and operatives of al-Qaida passed through, Korengal was not a major haven, said Maj. James Fussell, a former Army Special Forces soldier who spent nearly two years fighting here, from 2004 to 2005 and again from 2008 to 2009. He recently was co-author of an analysis of the mission in Kunar and Nuristan for the Institute for the Study of War. 'Occasionally a Taliban or al-Qaida member was transiting through that location, but the Korengalis were by no means part of the insurgency,' he said. 'Unfortunately, now they are, because they were willing to accept any help to get us out.' American commanders sporadically discussed closing the base almost since it was put there, but over the last 18 months the plan was pushed by Col. Randy George, who commands Task Force Mountain Warrior, which is responsible for four eastern Afghan provinces: Kunar, Nuristan, Nangarhar and Laghman. 'We're not going to go deep into these valleys and bring them into the 21st century in a couple of months,' said George, who determined early on that keeping forces in the Korengal and in the Kamdesh region was not an effective way to use resources or win over local people. Senti concurred. 'Realistically no one needs to be there,' he said. 'We're not really overwatching anything other than safeguarding ourselves.' The current company commander, Capt. Mark Moretti, Company B, Second Battalion, 12th Infantry Regiment, said he still hoped that his efforts to connect the Korengal elders with the district center in Nangalam would bear fruit, but other soldiers expressed skepticism. 'They are connected to the district government now a little bit,' said 1st Sgt. Bryan Reed, Company B, Second Battalion, 12th Regiment. 'But it's not one of their priorities.' Looking back, soldiers say the effort shows how choices made from a lack of understanding or consultation with local people can drive them into the arms of the insurgents. 'We had the best intentions, but when you don't fully understand the culture' it is impossible to make the right choices, Fussell said. A number of the infantrymen who fought here ruefully accept that the time has long passed for the military to spend lives and resources in a small and isolated valley that could not have been won without many more troops. 'It is frustrating, because we bled there and now we're leaving,' said Capt. John P. Rodriguez, who as a first lieutenant served there with Company B, First Battalion, 26th Marines. 'So you question: Were those sacrifices worth it? But just because you lost guys in a place, doesn't mean you need to stay there.' 