Three Rivers Stadium dominates this view of the Golden Triangle. (Dale Gleason/The Pittsburgh Press) View of the North Side, Three Rivers Stadium and the Golden Triangle. (Dale Gleason/The Pittsburgh Press) View of the Golden Triangle and Hill District. (Dale Gleason/The Pittsburgh Press) West End Bridge, the North Side and the Ohio River. (Dale Gleason/The Pittsburgh Press) The South Side. (Dale Gleason/The Pittsburgh Press) The ghostly outline of Forbes Field. (Stewart Love/The Pittsburgh Press) Public housing units. (Stewart Love/The Pittsburgh Press) The Allegheny River and Herr’s Island. (Dale Gleason/The Pittsburgh Press) Cathedral of Learning and Oakland. (Stewart Love/The Pittsburgh Press) Pitt Stadium and Oakland. (Stewart Love/The Pittsburgh Press)

On the eve of Summer Solstice in 1974, a low-pitched hum emanating from above caught the attention of Pittsburghers walking the streets of the Golden Triangle. People squinted upward into the haze and saw a stumpy silver cigar crawling across the sky. This was the blimp Mayflower, smallest and oldest of the Goodyear fleet, paying a visit to the Steel City.

Crammed into the airship’s gondola were at least three photographers — Dale Gleason and Stewart Love of The Pittsburgh Press, and Bill Levis of the Post-Gazette. Gleason and Love loaded their cameras with color film. This was a rare opportunity to photograph the city from a stable, slow-moving platform 1,000 feet in the air.

We recently located Gleason and Love’s original negatives in a dusty box we carted out of our old building on the Boulevard of the Allies. Under normal circumstances, we’d wait to post the pictures closer to the anniversary of their creation in the summer, but the images generated so much excitement among the Digs staff that it seemed unfair to keep them hidden in a file.

The Mayflower circled Pittsburgh at 35 to 40 miles per hour. Gleason, using a medium-format camera with a wide lens, shot a series of spectacular pictures that captured a city in awkward stages of development, as if stuck in a sort of civic puberty. Point State Park and its fountain had yet to be dedicated (this would happen in August). Portions of the city remain industrial brown. Wisps of smoke hover in the Mon Valley.

Without the playful modern buildings that define today’s skyline — Fifth Avenue Place, PPG Place, for example — the city skyline appears dull and utilitarian. Rising above the triangle’s base, U.S. Steel Tower seems a bit lonely and forlorn, the gawky kid who had a sudden and embarrassing growth spurt.

Then there’s Three Rivers Stadium. Four years young, the squat tube of concrete, surrounded by a vast plain of available parking, dominates two of Gleason’s pictures. We can peer into the stadium and see its orange, yellow, red and blue seats, the green of its baseball diamond. It resembles a gaping portal into another universe. Or perhaps just a drain.

Another Gleason photograph shows Manchester, the West End Bridge and a tangle of roads that were surely a headache to navigate.

The Mayflower turned south and east, making its way over the South Side. From here we can see the Civic Arena bubbling up in the Lower Hill District. Over Oakland, Love shot a picture showing the ghostly tan outline of Forbes Field, demolished three years earlier. Pitt Stadium appears ancient and magnificently functional. Look closely at pictures of the Cathedral of Learning and you’ll see the Syria Mosque lounging in the background.

So much of what the photographers captured on film that day was doomed. So much was yet to be. Glory and pain were in our very near future.

Within a year the Steelers would make the first of their many Super Bowl appearances and make Three Rivers Stadium home to greatness and legend. The city would, in the next decade, lose its industrial brown and thousands of jobs and struggle into a new identity.

The Mayflower blimp that hovered over our city that day experienced its own moment of fame and glory (or infamy) in 1977, when it appeared in Super Bowl scenes filmed in Miami for the thriller movie “Black Sunday.” Two years later, the blimp was destroyed when high winds ripped the airship from its moorings during an appearance in Mt. Pleasant, Iowa, and sent it rolling, irreparably broken, into a cornfield.

Gleason and Love, too, are gone (Gleason died in 1996; Love in 1981). We consider their images, colorful and breathtaking evidence of who we once were, as a gift to us during this holiday season.

(See Gleason’s pictures in greater glory on the Post-Gazette’s wideview page.)