In 1971, Ed Garvey published Appalachian Hiker: Adventure of a Lifetime, an account of his Appalachian Trail thru-hike, spurring interest in the AT and thru hiking. New innovative, lightweight outdoor gear began to appear in stores, making it easier for people to get out on the trail. The Allentown Hiking Club was a beneficiary of this enthusiasm for hiking. In December 1970, the club had 129 members. By December 1975, membership climbed to 333, and in December, 1978, AHC boasted 591 members.

This decade was the decade of the series hike. In the fall of 1971, Earl Raub began a series of Appalachian Trail hikes covering the Susquehanna to Delaware Rivers. The following year Raub offered an AT series from the Delaware to the Hudson River.

Raub, who led more AHC hikes during this decade than any other member, again led hikes covering the entire AT in Pennsylvania in 1974 and 1976. In between, Dick Snyder led a New Jersey/New York AT series in 1975. Raub repeated the NJ/NY series again in 1977. Several club members co-led the Pennsylvania AT series once more in 1978. The enthusiasm for series hikes spread to other longer trails. In 1972, and again in 1975 and 1978, club members had the opportunity to hike the entire Horse Shoe Trail.

As a result of these hikes, quite a few club members earned Keystone Trails Association hiking awards. Raub also organized two "all in one day" hikes. On May 2, 1976, club members divided into teams to hike the entire Horse Shoe Trail, and on April 4, 1977, the club covered every foot of the Appalachian Trail in the Commonwealth. After each hike, Raub compiled trail condition reports that were submitted to the maintaining clubs. To celebrate the U.S. bicentennial in 1976, Dick Leach volunteered to organize historic hikes. This series culminated in a chartered bus trip to Philadelphia and Valley Forge, where club members hiked through the city’s historic district and park.

Harold Croxton was appointed Trail Chair in 1974. In an effort to curb litter and inappropriate shelter usage, he initiated a schedule of weekend shelter caretakers, whose presence deterred misuse. A half-mile trail relocation between Jacksonville Road and PA 309 was completed in May, 1976. The increase in overnight shelter usage had an impact on the Allentown Shelter, which was equipped with four wire bunks and had a dirt floor. In October, 1973, Dick Snyder organized a shelter work trip to replace the deteriorating back wall of the shelter and tear out the bunks and install a wooden floor that would double the sleeping capacity of the shelter. In July, 1975, club members rebuilt the fireplace, packing in 80-pound bags of concrete two miles.

The Allentown Shelter spring dried up each summer, presenting problems for backpackers. In April, 1978, Croxton reported that a never fail spring had been located and a yellow trail would be blazed to it.

In 1978, the Philadelphia Trail Club was planning to abandon the Outerbridge Shelter on the west side of Lehigh Gap. AHC voted to assume maintenance of the shelter, and Nick Rosato volunteered to chair the rehabilitation effort, which included work trips to install a floor, replace the roof, rebuild the fire ring, and clean up the shelter area.

The New Tripoli Shelter, maintained by the Blue Mountain Eagle Climbing Club, was torn down in August, 1979, and AHC agreed to assume responsibility for maintaining a campsite at that location.

In October, 1977, Raub organized a weekend work trip to remove the debris from an airplane crash near Little Gap. More than 1400 pounds of metal was salvaged and sold for $301.85. The club added $100 and sent the proceeds to the Appalachian Trail Conference. In addition, to support the ATC move from Washington, DC to Harpers Ferry in 1976, club members raised more than $320 to contribute to the purchase of the new headquarters building.

In July, 1974, Earl Raub became AHC's first AT 2000 Miler. One month later, Bob Reinhard also earned End-to-End status. They were followed by Croxton (1976) and Barbara Wiemann (1977). In 1977 Reinhard became the first AHC member elected to the ATC Board of Managers.

As the decade drew to as a close in 1979, the National Park Service acquired its first tracts of land in the AHC trail section (four parcels near the Jacksonsville-Snyders Rd.) to protect the AT corridor.

In 1975 the club obtained permission to meet at the Pioneer Community Center and built a storage cabinet. With an available meeting room and an increasing membership, the club began holding monthly meetings the next year and Gene Scharle organized a club library.

The Allentown Recreation Bureau presented the Senator John Van Zant Memorial Award to the club in 1976 in recognition of AHC's outstanding recreation program (in 1976 the club offered 140 activities). AHC offered its first club T-shirt in 1978. Finally, the club made an important financial decision late in the decade, doubling the club dues from one dollar to two dollars for 1979.