It had five inclines on either side of the drainage divide running athwart the ridge line from Blair Gap through along the kinked saddle at the summit into Cresson, Pennsylvania.

The Railroad utilized cleverly designed wheeled barges to ride a narrow-gauge rail track with steam-powered stationary engines lifting the vehicles.

The roadbed of the railroad did not incline monotonically upwards, but rose in relatively long, saw-toothed stretches of slightly-sloped flat terrain suitable to animal powered towing, alternating with steep cable railway inclined planes using static steam engine powered windlasses, similar to mechanisms of modern ski lifts.

Considered a technological marvel in its day, it played a critical role in opening the interior of the United States beyond the Appalachian Mountains to settlement and commerce.

Occasionally the rails were laid upon the extreme verge of a giddy precipice; and looking from the carriage window, the traveler gazes sheer down, without a stone or scrap of fence between, into the mountain depths below .

It was very pretty travelling thus at a rapid pace along the heights of the mountains in a keen wind, to look down into a valley full of light and softness; catching glimpses, through the treetops, of scattered cabins; .

It was amusing, too, when we had dined, and rattled down a steep pass, having no other moving power than the weight of the carriages themselves, to see the engine, released long after us, come buzzing down alone, like a great insect, its back of green and gold so shining in the sun .

[10] Construction on the New Portage Railroad, a 40-mile realignment to cross the Allegheny Ridge bypassing inclines, started in 1851 and cost $2.14 million.

The PRR raised sufficient investment and had enough quick success that they bought the existing Portage railroad and other parts of the Main Line of Public Works from the state on July 31, 1857.

"[11] Nearly half a century later, the graded roadbeds of the descending section east of the Gallitzin Tunnel were re-railed with standard gauge freight tracks.

Pennsylvania Railroad successor Conrail abandoned this line to Hollidaysburg and most of the branch trackage along the Juniata River in 1981 and removed the rails.

[12][13] The National Historic Site was established on 1,296 acres (524 ha) in 1964 and is about 12 miles (19.3 km) west of Altoona,[14] in Blair and Cambria counties.