The Hürtgen Forest is a 50 square mile area in Belgium and western Germany, bound roughly by a triangle Aachen-Monschau-Düren. The area is quite rough, with swiftly-flowing creeks in deep valleys with heavily-forested banks; on top of the bald ridges, lay small farming villages. Much of the area was a state-owned tree farm, which meant that the trees, 75 to 100-foot tall conifers, were planted very close together, obscuring the sunlight and forcing men to stoop to clear the low branches. Effective control of units larger than platoons in such a forest was nearly impossible, and men were vulnerable to artillery and mortar shells bursting in trees, resulting in a hail of deadly shrapnel and wood splinters. Operations of armor and aircraft were restricted; tanks were limited to the few roads and firebreaks on the forested banks and ridges, which were predictably pre-sighted for artillery and heavily mined. Once troops entered the forest, they became basically invisible to aircraft, which for the most part neutered American air superiority.

The main objective in the area besides the forest itself was the dams which controlled the flow of the Roer River, on the eastern edges of the forest. If water from the dams was released in full, it could have rampaged downstream to the north and delayed a crossing of the Roer for up to several weeks along the entire First and Ninth Army fronts. The dams themselves were not listed as an objective of a ground attack until early December 1944, nearly four months after attacks into the forest began. A handful of air attacks on the dams were carried out, but they were largely ineffective. The main reason for fighting in the forest beforehand was that it posed a threat to the right flank of Courtney Hodges' First Army and as a result needed to be cleared.

As the Hürtgen Forest is in close proximity to the Westwall, it is studded with many concrete bunkers, which are often almost invisible, built into hills and camouflaged with foliage. German forces in the area had constructed additional bunkers and fighting positions from dirt and heavy logs (which were, like concrete positions, almost invulnerable to all but point-blank tank and artillery fire) and sowed the area with mines. One particularly devilish minefield was the Wilde Sau, (wild boar) meant to deny road access to the village of Hürtgen, where all different types of mines were laid with no apparent pattern. The triggering of one mine usually caused the sympathetic detonation of several others, causing the destruction of whole groups of men.

Fighting in the forest began in September 1944 with an effort by the U.S. First Army's V Corps and the 9th Infantry Division, to seize the Roer crossings at Düren. The division, after two months of fighting, was unable to eject the Germans from even the edges of the forest, suffering heavy losses in the process (4,500 casualties for a gain of only about 3,000 yards) The battered 9th was replaced with the 28th Infantry Division in early November 1944. The 28th's mission was to capture the town of Schmidt, nearly in the center of the forest, and provide a starting line for the capture of the Roer dams (the reservoirs are visible to the southeast when one stands just outside Schmidt) After heavy fighting during the period November 2-9, the division was relieved by the 8th Infantry Division, having lost all the territory it had gained in its initial attack in addition to 5,684 casualties. The 112th Infantry Regiment was basically destroyed, suffering losses of 167 killed, 719 wounded, 431 missing, 232 captured, and 544 non-battle casualties out of a starting strength of roughly 3,100. German forces in the area (the remains of several infantry divisions) were also severely beaten, and the ability for American units to have infantry replacements at their beck and call gave them the upper hand.

With the failure of the 28th Infantry Division's attack, responsibility shifted to First Army's VII Corps with a greater emphasis on the northern part of the forest. The main part of the attack was carried by the understrength 4th Infantry Division, (the 12th Infantry Regiment had joined the 28th Infantry Division during their most desperate hour, was mauled, and was in no shape to take part in the attack) in the north-center of the forest, with the 1st and 104th Infantry Divisions in support on the mostly open ground even further to the north. The objective was the original one as defined in September; Roer crossings at Düren. Preceded by massive coordinated artillery and air bombardments, fighting in the 4th Infantry Division's sector ground to a halt by late November 1944 after the capture of the villages of Grosshau, Kleinhau, and Bergstein, and V Corps was called upon again; the 83rd Infantry Division relieved the 4th, (which had suffered 4,053 casualties during the period November 16-December 3, including 432 dead and 255 missing) and the fresh 8th Infantry Division and 5th Armored Division were committed to capture the village of Hürtgen and the area overlooking the dams, providing a jumping-off point for other units of the 5th Armored Division to sweep down onto the open ground in front of the Roer. German opposition in the Hürtgen Forest area, despite being very fragmented, (German "infantry divisions" in this area were often conglomerations of three or four destroyed units, the next one moving into the area picking up what remained of the previous one) was extremely fierce, intensifying in late November and early December 1944; it was imperative that they hold the Americans at bay on the approaches to the Roer River, or the entire southern flank of their secret attack (Unternehmen Wacht am Rhein) would be threatened.

The Battle of the Hürtgen Forest was interrupted for nearly two months by the Battle of the Bulge, with units in the area holding a defensive posture; the 78th Infantry Division, sweeping in from the southwest, captured the Roer dams in February 1945, which had been hastily abandoned. The dams' floodgates had been partially opened by the retreating Germans, which, as predicted, delayed a crossing of the Roer River, although the delay was not as severe as feared. The American failure to see the dams within the forest as the true objective rather than the forest itself contributed to the uncoordinated, hellish fighting; the 9th Infantry Division's assault in September and October 1944 was not really an earnest attempt to clear the forest, just an attempt to continue the pursuit successes of August and September 1944 on the seemingly weak Germans. American troops were often reluctant to move under fire unless supported by overwhelming armor and air support; new replacements were brought up in the morning, only to be dead by nightfall.

Sources:

A Dark and Bloody Ground: The Hürtgen Forest and the Roer River Dams 1944-1945, by Edward G. Miller

United States Army in World War II, European Theater of Operations: The Siegfried Line Campaign, by Charles B. MacDonald

Three Battles: Arnaville, Altuzzo, and Schmidt, by Charles B. MacDonald

The Battle of the Hürtgen Forest - Scorpio's Website