They race down the river in floodwaters. They bob about in rafts of debris. They lie half buried in a muddy shoreline, and even hang strings from overhanging branches. They are plastic water bottles, the Potomac River’s iconic trash.

Two thousand miles away, in the desert along the Mexico-New Mexico border, artist Jami Porter Lara also keeps an eye on plastic water bottles.  These are big two-liter ones, not the 16-ounce size generally found in the Potomac.

Most of the Potomac’s plastic bottles had been swept off curb sides or parking lots and into creeks, and eventually ended up in the river. A few may have been tossed directly into the current by fishermen or picnickers. Either way, they number in the many thousands, a never-ending downstream migration of plastic.

The bottles on the desert border were also the product of a migration, but in this case of people from Mexico and Central America heading north. For them, water in plastic water bottles is not just a convenience, but a necessity. Without it they would perish from thirst. When they cast aside an empty bottle, they aren’t littering. It’s part of their fight to survive.

For Porter Lara, the plastic bottles stand as a testimony to a human drama of hope and perseverance, and this is one reason why she is drawn to them.

There are other reasons, as I discovered in her exhibit called “Border Crossing,” which is now in its final days at the National Women’s Museum in Washington, D.C. For her, these humble, everyday objects have inspired her to create art that invites us to cross borders of human perception and understanding. Her vision is something that our own Patowmack the Trickster—himself a master of shape-shifting—would appreciate.

Crossing borders. One of these borders is time. Many of Porter Lara’s bottles, with their twisting, organic forms, evoke mankind’s early use of gourds to transport water. Others recall ancient amphoras. Her works also reference the pots made by pre-Columbian peoples, shards of which also lie scattered in the Southwest border desert. But all are unmistakably representations of plastic water bottles, with their threaded tops and the five radiating indentations that lend rigidity to their plastic prototypes.

Another is the border between art and trash. Porter Lara makes her pots the traditional way. She digs the dry, crumbly clay out of the side of a stream bed, laboriously mixes it with water, and strains out the impurities. Then she molds the bottom of the pot in a plaster cast she formed from the bottom of a plastic water bottle.

She forms coils between her palms, which she then presses to the molded base and spirals up what will be the sides of the pot, pinching them together as she goes. After the pot dries she burnishes the surface to a sheen with a smooth stone. Lastly she fires the pots in an outdoor pit of smoldering wood, which she covers to reduce oxygen so that the clay surface turns black.

She calls her pots “contemporary artifacts,” combining ancient material and technique with present day interpretations. “By making plastic bottle forms out of clay, making them appear more like what we perceive as artifacts, my purpose is to hasten our awareness of the inevitability that these, too, will belong to the past,” says Porter Lara in materials prepared for the exhibit.

Man and nature. The final and perhaps most elusive border is that between nature and human artifice. Porter Lara’s pots express the idea that nature is not something apart from people. It is not pristine, nor should it be. Her pots invite us to view humankind is a part of the natural world.

“Saying that humans are only pollutants is a failure of imagination,” she says. “Yes, we’re destructive, but we’re also creative. . . . I want to create the possibility that we can see things differently and contribute to the world.”

I agree with Porter Lara about the ambiguity of trash. For a long time I have resisted condemning the flotillas of plastic bottles and other man-made detritus in the Potomac River. Instead, I look at it with interest.

Of course I wish there was no trash, but not because it makes the river less lovely—that would take an awful lot more trash than what we have now. Mostly I don’t like trash because of what it says about the people who live in the river’s watershed. We are—as Porter Lara says—a part of nature, an idea which I find both uplifting and depressing.