Khyber, located between Afghanistan and Pakistan's northwestern Khyber-Pakhtunkhwa province, had been in the control of al-Qaeda linked Taliban and Lashkar-e-Islam militants when the offensive was launched last year.
The military operation, codenamed Khyber-2, was completed on June 15, the first anniversary of Operation Zarb-i-Azb in North Waziristan, Dawn newspaper reported.
But questions remain whether the military gains could be sustained over a long period in the absence of a dependable administrative system.
It took control of the three passes from Afghanistan into Khyber's Tirah valley -- Mzatal, Kandao Gharibi and Dramudrad situated at 7,300 to 9,300 feet altitude above the sea level.
During the campaign, military lost more than 50 personnel, including officers while about 100 or so were wounded.
In one single fight for the control of Khyber Sanghar, called the Kidney Ridge by the military due to its shape, the military lost 11 men, including a major. The areas were heavily mined with at least a mine every 15 metres.
It said militants hiding in remaining pockets of Kachkol and Rajgal are now being targeted through precision strikes.
The operation is believed to have a calming effect in neighbouring Peshawar division, where the number of terror incidents dropped from 136 in the first quarter of 2014 to 44 in the corresponding period this year.
However, the big challenge for the Pakistan Army and the government is to sustain the peace by keeping the insurgents away and developing the impoverished region.
Lashkar-e-Islam leader Mangal Bagh is inciting violence in Khyber via evening speech delivered through an FM transmission from his new home.
