is for Allegheny, as any Pittsburgher would guess, all 325 miles of this winding river’s course. The name, bestowed by Native peoples whose interactions with the waterway go back many centuries, translates to something akin to “fair waters.” From a headspring on a Potter County hillside in northwestern Pennsylvania, the Allegheny gathers enough water from a small section of western New York and a large portion of Western Pennsylvania to conclude her run at Pittsburgh’s Point with flow averaging 2 billion gallons a day.

is a bountiful letter when it comes to our rivers’ scenery. Boats, barges, buoys and bass, plus bike trails and, if you know where to look along the bank, even beavers. But bridges belong atop any “B” lists because of their abundance, importance as transportation links and beauty. Fifty-three main channel spans are located on the combined 200-mile stretch of Allegheny, Monongahela and Ohio rivers known for commercial purposes as the Port of Pittsburgh. Our region’s bridge richness is recognized by engineers throughout the world, which is one reason the International Bridge Conference is held annually in Pittsburgh.

 could be for catfish, carp, canoes and the wonderfully concise geographic term “confluence.” Coal captures this category’s crown, however, for this combustible rock’s critical role in the founding and growth of Pittsburgh’s industries, the resource’s continued importance in generation of electricity and the ongoing water quality problems associated with long-abandoned coal mines. A common cargo of rail cars and barges, coal is composed of the highly compacted remains of lush tropical vegetation that grew here some 300 million years ago when Western Pennsylvania was coastal plain bordering a vast inland sea.

 is for dams, the series of massive water barriers designed and maintained by the U.S. Army Corps of Engineers to create dependable depths of at least 9 feet throughout our rivers’ navigation channel. Damming efforts date to 1877 when construction of a federally funded Ohio River dam began at Davis Island, 4.5 miles downstream from the Point. Today, a dam 6 miles down the Ohio near the town of Emsworth creates a pool that stretches nearly six miles upstream on the Allegheny and more than 10 miles upstream on the Monongahela.

 is for elevation, the distance that water in our rivers drops, under the pull of gravity, to reach the level of the sea. At normal levels, surface waters around Point State Park are 710 feet above sea level, a vertical distance that can be graphically imagined as more than three-quarters the height of the U.S. Steel Tower. Waters flowing through Pittsburgh descend this distance over a course of more than 1,900 miles to reach the Gulf of Mexico.

 is for fish. More than 50 species can be found in the far-reaching watershed drained by Pittsburgh’s rivers. Some are familiar, such as small-mouth bass and walleye; others have funny-sounding names like flathead catfish, mooneye and river redhorse.

Floods must also be considered here, for the impacts that linger in our collective memory of exceptional high-water events in 1936 and 1972. Through the development of flood-control dams on major river tributaries and on the main stem of the Allegheny above Warren, the Army Corps of Engineers has worked to reduce the crests of devastating floods.

 is for glaciers, the continent-wide,sometimes mile-thick ice sheets whose grinding southward advances and melt-back northward retreats are responsible for the topography of the Pittsburgh region. Before the great ice action cycles began some 100,000 years ago, the waters of Western Pennsylvania flowed north toward the present location of Lake Erie.

 is for hillsides, specifically the steep wooded slopes of our river valleys. As parts of the landscape fabric that both frame and offer vantage points for long-range views, these ribbons of rugged terrain change appearance with the seasons, and also lessen storm-water runoff and reduce the buildup of summer heat.

 is for islands, more of them than most people would imagine. A drawing from 1755 depicts an island just off the North Shore where the Allegheny surrenders her flow to the Ohio, and a map from 1795 indicates that a Monongahela River sandbar the length of Downtown was sometimes used to grow buckwheat.

 is for journeys, many thousands of them headed downriver and west. River connections to the interior of the North American continent helped Pittsburgh earn an early reputation as a “Gateway to the West.” The initial journal entry for the epic Lewis & Clark Expedition notes Pittsburgh as the departure point on Aug. 31, 1803.

 is for kayaks. Weather and river conditions permitting, it’s not unusual to spot paddlers maneuvering modern versions of the traditional Inuit sealskin boats on the waters around Downtown. Credit outdoor-oriented clubs, whose experienced members train novices, or praise the entrepreneurial spirit of those who rent the solo craft, but the proliferation of the colorful, muscle-powered boats is unsinkable proof of changing attitudes about our rivers.

 is for locks, the massive double-gated water chambers that lift and lower river traffic from one pool to the next at each navigation dam. The chambers are long, high-walled concrete rectangles, built into the river bed along an axis perpendicular to, and across the fall line of, the dam. Through the careful operation of end gates and water valves, the chamber can be gradually filled to match the upper water level or drained to match the lower.

is for navigation, a reminder that safe travel on moving water involves more than a decision to go with the flow or against the current. For those who have learned how to read them, basic guides for maneuvering watercraft stand or float in plain sight. The Army Corps of Engineers maintains those around locks and dams; the Coast Guard takes responsibility for all others.

 is for Ohio. This mighty river, whose Native American name refers to her beauty, flows 981 miles from Pittsburgh to join the Mississippi at Cairo, Ill. For all but 40 Pennsylvania miles, waters mixed in Pittsburgh serve to divide states — Ohio from West Virginia and Kentucky, and Kentucky from Indiana and Illinois.

 is for Port of Pittsburgh. For shippers familiar with the intricacies of shipping bulk cargo by barge, the name denotes the nearly 200 miles of commercially navigable waterways that cross or extend into 11 southwestern Pennsylvania counties. This district boasts more than 200 river terminals, barge loading and unloading facilities equipped with specialized cranes and conveyors. By currently available figures, the Port of Pittsburgh is the second-busiest inland port, and the 19th-busiest port of any kind, in the nation.

 is for quartz, a mineral whose abundance and accessibility was crucial to the development of our region’s glass industry. Silica is a basic ingredient for glass production, and quartz is a chemical compound of silica and oxygen. As early as 1797, glass furnaces in Pittsburgh utilized quartz sand dug from the beds and bars of the nearby rivers.

 is for river recreation, some aspects of which we celebrate with an annual regatta. Current options are fishing, all kinds of boating, including even rowing competitions, and increasingly bicycling and hiking along some routes that were once railroad rights-of-way.

Steel tops all S selections because of the enormous amount of regional riverfront once devoted to the production, shaping, storage and shipment of this critical metal. In an era when steelmaking in Pittsburgh survives on a relatively smaller scale, proof of the smokestack industry’s once ubiquitous presence here can be found in the ongoing efforts to assemble the Rivers of Steel National Heritage Area. This project, formally created by Congress in 1996, seeks to preserve, manage and interpret the historic, cultural and natural resources related to Big Steel and its attendant industries.

 is for tributaries. In a classic example of a drainage system described as dendritic for its resemblance to the branching of a tree, our rivers receive their waters from contributors large, medium and small. The waters the Ohio carries west are the collective flow of several smaller rivers, dozens of creeks that would be called rivers in other parts of the country and a myriad of named runs and anonymous rivulets.

 is for underground river, the mysterious, but ultimately inaccurate, description for the thick layer of water-saturated sand and gravel that underlies a broad swath of Allegheny and Ohio River flood plain. The air conditioning systems of several Downtown buildings and the confluence-crowning fountain in Point State Park utilize this continually recharged water supply.

 is for views, upstream, downstream and across our river valleys. Rivers are a constant yet ever-changing element of such valley views. The water surface changes color and even texture depending upon the season, weather, water level, temperature and time of day. Whether cloaked in light mist on a September morning, ice-rimmed during a January cold snap or high, latte-brown and marbled with floating debris after three days of June rain, our rivers can supply nearly infinite variations to otherwise familiar scenic views.

 is for watershed, the complete land area draining to a particular body of water. A map exercise of back-tracing tributaries to chart the bounds of the upper Ohio River watershed is in some ways akin to exploring the linked pages of an information-laden Web site.
Two river-focused sites worth investigating are:

• U.S. Army Corps of Engineers, Pittsburgh District

• 3 Rivers-2nd Nature, STUDIO for Creative Inquiry, Carnegie Mellon University

 is for xylem, the woody tissue of trees and other plants that conducts water and nutrients. Though it’s hard to imagine today, the trees that once grew in the rich soil of our river flood plains were massive. A 1749 note made by a priest accompanying a French military expedition down the Allegheny and Ohio offers some indication: He observed 20 men sharing a meal in the hollow trunk of a riverbank tree.

 is for Youghiogheny River, the Monongahela tributary whose Native American name refers to her winding course and rapid flow. Although the Yough flows some 132 miles from headsprings on the flank of Maryland’s Backbone Mountain to her junction with the Mon near McKeesport, for thousands of whitewater fans the river’s essence can be found in an 8-mile section of boulder-framed rapids near Ohiopyle where tumbling waters have carved a deep gap through Pennsylvania’s most westerly Appalachian ridge.

 is for zigzag, a capsule description of our rivers’ wandering courses. It’s a phenomenon that invites firsthand investigation. Use a finger to trace the near looping meanders on a road map or, from a prominent hilltop, follow a less extensive set of linked bends with your eyes. Better yet, experience the waters’ eventual movements toward nearly every compass point aboard one of the myriad forms of watercraft that call Pittsburgh’s rivers home.