The River You’ll Run Beside

In 2007 the Santa Fe River was named the most endangered in America. In 2026 the half marathon runs beside it.

On the Santa Fe River, Agua Fría Village, and why the 2026 course came home to the water.

In April 2007, a conservation group in Washington, D.C. published its annual list of America’s Most Endangered Rivers. At the top — ahead of the Chesapeake tributaries, ahead of anything in the Everglades — was a river most Americans had never heard of, in a city better known for adobe and green chile.

The Santa Fe River. Number one. A river that, for much of the year, wasn’t really there at all.

If you run the 2026 Santa Fe International Half Marathon, you will spend your morning in that river’s corridor. It’s worth knowing what happened here.

A river that used to run all year

The Santa Fe River was once perennial — water in it every month, every season. That held until roughly the 1700s. By the twentieth century it had become a seasonal waterway, and by 2007 the stretch running through town was, for long periods, a dry channel of sand and cobble with a road running alongside it.

The causes were the ordinary ones: diversion, damming upstream, groundwater pumping, and a century of asking a small high-desert river to support a growing city. Add severe channel erosion, and you get a watercourse that had been engineered into something closer to a drainage ditch than a river.

That’s the thing about a dry riverbed. It doesn’t look like a crisis. It looks like ground.

A village named for cold water

The irony is sharp, because this valley is named for its water.

Agua Fría — cold water — takes its name from the natural springs that rise here. Spanish settlers established the village in the early eighteenth century, but they were not the first. Archaeologists have found pit houses and the remains of Pindi Pueblo in the Agua Fría area; people were farming this floodplain centuries before Spain arrived, for the same reason the Spanish came — the water was reliable.

Agua Fría Street itself traces part of El Camino Real, the road that carried traders between Mexico City and Santa Fe for generations. Later the Santa Fe Trail brought wagons through from Missouri. This has been a corridor of movement for a very long time. On September 20 it will carry more than three thousand runners.

The village is now a designated historic district, and it is not a museum piece — it’s a working community of homes, acequias, churches and small farms, which is exactly why we ask you to treat these roads as somebody’s front yard. Because they are.

What restoration actually looked like

The recovery of this stretch didn’t come from a single grand gesture. It came from unglamorous, expensive, patient work.

Santa Fe County acquired roughly a mile of river channel in Agua Fría and displaced an active gravel mine from the reach — you cannot restore a river while it is being dug up. Work on the San Isidro River Park began in 1998. Crews installed structures to arrest the erosion that had cut the channel deeper and deeper, then planted hundreds of cottonwoods and willows along the banks. A trail now runs along the river between the parking area and Agua Fría Park — the same Santa Fe River Trail you will run on race day, and the park at the end of it is on the course.

Elsewhere in the village, eighteen volunteers moved sixty tons of sandstone and donated more than eight hundred hours to build a stone tower honoring Agua Fría’s history.

Nobody restores a river in a single season. Cottonwoods take decades. What you see in the corridor now is the visible part of a twenty-five-year argument that this river was worth keeping.

Why the course came here

For years this race ran from the foothills down into the city — a fine course with a great view and a logistics tail that required buses at half past five in the morning.

The 2026 route does something different. It stays in the valley. It runs through Agua Fría Village, then out and back along the Santa Fe River Trail, straight through San Isidro River Park and Agua Fría Park — the two parks the restoration created — and it finishes at Reunity Resources, a nonprofit farm on this same ground that works in regenerative agriculture, food systems and environmental education.

There’s a neatness to that we didn’t entirely plan. You will run past cottonwoods planted by people who believed a dead river could be brought back, through a village that has been farming this floodplain for a thousand years, and finish at a farm that is still doing it — and then eat green chile in the shade of their trees.

It is not the fastest course we have ever run. It climbs 651 feet to a turnaround at mile nine and makes you earn the way home. But it is the one that best explains where you are.

When you’re out there

Look for the cottonwoods. The big ones along the channel are the point. Every one was planted by somebody who wouldn’t live to see it full-grown.

Mind the acequias. The irrigation ditches threading the village are centuries-old shared infrastructure, still maintained by the families who depend on them. Don’t step in them.

Say good morning. The people watching from their driveways on race morning are the reason we can close these roads. Many of their families have been here longer than the state of New Mexico.

Carry your trash to an aid station. We are running through a watershed that took twenty-five years to bring back. Let’s not leave gel wrappers in it.

The Santa Fe International Half Marathon is Sunday, September 20, 2026. The Half Marathon and 3-Amigos Relay start together at 7:30 AM from Romero’s Park, finishing at Reunity Resources Farm in Agua Fría. The 5K starts at 8:00 AM at Reunity Resources Farm. The free Kids 1K Dash runs Saturday afternoon at Railyard Park downtown.

Read The Run Santa Fe Story → · See the 2026 course →

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