I love stairs, especially public stairs. I just can’t pass by a public staircase without giving it a quick run. It seems like my right, my pure civic pleasure. Urban stairways start where the streets dead-end, taking you all the places cars can’t.

Hilly Seattle has no less than 500 public stairways. They travel up woodsy greenbelts, descend under bridges, skirt backyard junk heaps and elegant private gardens. I decided to make it my summer project to hike them all—the complete stairway circuit, my own Pacific Crest.

My first stop was the Roadway Structures Division of the Seattle Department of Transportation, where a very pleasant engineer named Ainalem Molla oversees the city’s public walkways. His three-ring binders contain an individual file on each and every staircase, complete with photos, inspection reports, citizen letters, and other historical info. He also has a computer database that can sort the stairways by street address, stairway type (timber frame, concrete slabs, composite, etc.), railing type (pipe, timber, etc.), number of “threads” (the engineers’ term for “steps”), and overall stairway length (which helps determine steepness).

I asked Ainalem to print me out a list of all the city staircases with 100 threads or more. There were about 50. I vowed to launch myself into summer by tackling them all in a single weekend. It would be like John Cheever’s “The Swimmer,” but with a happier ending.

I began on a Friday evening with Blaine and Howell, the twin trails that run up the western face of Capitol Hill, from Lakeview Avenue to 10th Avenue E. Blaine and Howell are the Mount Si of staircases: close by, well-maintained, and useful as training runs. But like any true adventurer, I was frustrated by their popularity and hungered for more remote pleasures.

Next morning I set my sights on the Hill’s eastern face. Here, amid the lovely homes of Leschi and Madrona, I found dozens of staircases and secret walkways that lift you all or partway up the Hill, traveling along the ghost routes of dead-end streets. One of my favorites was the all-terrain Pine Street trail: From a little lane called Evergreen Place, a high wooden trestle bridge takes you across a wild ravine; then, crossing Madrona Drive, you climb a tidy walkway between homes to Grand Avenue, up some stairs, and into a leafy interior, from which you emerge many threads later at 37th Avenue S. It’s Old World village travel at its best.

Another obscure staircase at the corner of 38th and Spring, in a wooded area off Madrona Park, serves as an excellent cross-trainer, with five steep flights, alternately sloped to the right and the left. A wide staircase beneath the I-90 bridge was overly groomed and charmless, like all the many useless parks that surround that boondoggle of a freeway.

Tearing myself away from the countless beckoning pathways (Charles . . . Norman . . . Dearborn!), I forced my way south. As with everything else, Rainier Valley has been slighted when it comes to stairs. There was only one on my list: rising disconsolately from S Adams Street, just off Rainier Avenue (roughly across from the Darigold plant), it was strewn with litter and rubble.

A few blocks from Cleveland High School, at the corner of S Lucille and 18th Street, was a more enticing climb, taking me gradually up Beacon Hill, through a greenbelt well-trampled with illicit-looking detours. Still farther south, where Rainier becomes a beach cruise, a long staircase rose from it at Cooper Street, offering some excellent views of the lake and the southern tip of Mercer Island.

Day One was done. I could climb no more.

As dawn broke the next day I continued sleeping. But by noon I was on the road again. Today I would take on the staircase equivalent of the Bugaboos: West Seattle. I headed straight for the pinnacle, the city’s largest staircase (some 228 threads) at 18th Avenue SW between Charlestown and Marginal Way. I expected grandeur. Instead I found a hideous descent, through weeds and brush, down a wrong-side-of-the-tracks hillside looking out at the underbelly of the Spokane Street Viaduct. The stairway bottom gave onto a dead-end trash heap, while the summit was watched over by a vicious Doberman and suspicious neighbors. Not recommended.

Far better was a long, long stairway that rises steadily up from the corner of SW Genessee and Delridge, alternating hot, exposed areas with cool shade and mossy steps. This little-traveled route also features excellent blackberries (in season). I ventured on along the westside peaks of West Seattle, known as Puget Ridge, an area of bleak homes, unfriendly natives, and numberless staircases, all of them pleasant but utility-like. With the afternoon expiring, along with my energy, I crossed over to the Alki side, where the handful of saltwater-scented climbs refreshed me.

After a Zatz bagel and coffee, I rushed to Queen Anne Hill, still hoping to complete my mission. But I was distracted by fatigue and by the seductions of routes that were not my own. A broad and elegant staircase, less than 100 threads, wooed me into the greenery at Comstock Place, just off Queen Anne Avenue. On Galer, I discovered that you could scale the entire hill, from Aurora all the way up to the TV tower, with an alternating trail of streets and stairs. And the best urban hike of all, I found, had no stairs whatever: From the seedy backside of Northern European Auto Repair on Aurora, a narrow muddy path, with an unsteady wooden railing, climbs steeply along the east flank of the hill, providing lovely views of Lake Union and, finally, at the summit, giving way to the mansioned splendor of Crockett Street.

Exhaustion overtook me. Magnolia would have to wait for another season. Yet the next day, after work, like the compulsive I am, I found myself driving through a pouring rain across the West Seattle Bridge and down Fauntleroy, where, I had heard, the ultimate stairway lay. I was not disappointed. Though my list from the city database rated SW Thistle Street at only 125 threads, it actually gave up some 350 threads of pure stair-climbing satisfaction, with inspiring look-backs at the Sound and the Vashon ferry dock.

Descending back to my car, I couldn’t help noticing that the nice white house at the foot of the staircase was for sale. This could be the start of a beautiful summer.