I was crammed into the back seat of a Subaru wagon Friday, bouncing down the tail end of the last dirt road along New Mexico’s Middle Rio Grande when the big marsh buggies emerged in the distance, blocking up the road’s end.

In the lexicon of the river’s “maintainers,” we were somewhere around “River Mile 55,” 32 river miles down the Rio Grande from San Antonio, which is the last reliably populated human habitation on New Mexico’s Middle Rio Grande; 55 river miles upstream from Caballo Reservoir, where the river mile counting begins. The marsh buggies, transplants from oil field work in coastal Louisiana, were a bizarre sight, perched on the edge of a desert river.

It was an odd party of adventurers, armed with a drone, some binoculars, cameras, a notebook, and the most important tool of our trade, a cheerful curiosity.

This stretch of the Rio Grande is not quite as forgotten as what we capitalize as “The Forgotten Reach,” the stretch of the river south of Fort Quitman, Texas. But it feels pretty forgotten, other than the odd Bureau of Reclamation or Middle Rio Grande Conservancy District maintenance crew, a few intrepid birders (and those paid to do Endangered Species Act bird surveys), the very occasional bike rider, and those skilled in finding out-of-the-way BLM camping spots.

Twenty-eight rivers miles downstream, Elephant Butte Dam plugs this stretch of the Rio Grande, an engineering feature completed in 1916 that defines the geomorphology of what I’m going to start calling my “forgotten reach.” The spot where we parked for lunch among the marsh buggies was underwater back in the late 1990s, representing the upper end of Elephant Butte’s near-full pool. The resulting sediment backup defines the strange back-and-forth of river behavior – what I love to call “the Rio Grande doin’ river stuff” – and “river maintenance.”

Beginning soon after Elephant Butte was built, the sediment backup here plugged the river channel, heavy flows of silt from the Rio Puerco, the Rio Salado, and myriad smaller desert arroyos filling the main channel, washing down until it hit the new base level established by Elephant Butte’s full pool, raising the valley floor, plugging the river.

In the 1950s, Reclamation dug a canal through the reach to move the water down more “efficiently,” where efficiency, perhaps rightly, was defined as getting water to the folks downstream who need it.

The pas de deux between the Low Flow Conveyance Channel and the main river channel has been going on ever since, not always happily from the point of view of the above-mentioned definition of efficiency. For nearly twenty years, the Reclamation and the New Mexico Interstate Stream Commission have hired the marsh buggy operators to dig a channel through all the muck so the river has a place to be.

Beginning sometime in the late 1990s (further research needed) a secondary channel formed along the western bluffs on this stretch of the river, originating in a leak in the human-built Conveyance Channel, which has become very popular with the birds – with the efficiency-minded water managers not so much. There’s a bit of a war of words about what to call it. My vote is for “Rito de Fray Cristóbal”, with “Fray Cristóbal” the name of the mountains to the east, but my Spanish is weak, drop your suggestions in the comments.

Reclamation is in the environmental review stage of a big project called the “Lower San Acacia Research Improvements (LSARI, and yes we try to pronounce it like a word that looks weird when you type it out – “el-sorry”) Project. The idea is to effectively rebuild this stretch of the Rio Grande at a cost of hundreds of millions of dollars.

For the purpose of the new book idea Bob Berrens and I are exploring, LSARI’s goals reflect, for storytelling purposes, a perfect mix of competing and conflicting goals:

• improve the efficiency of getting water to Elephant Butte for downstream users
• “enhance ecosystem health”
• manage future maintenance costs by getting the river itself to do most of the geomorphic work

For the purposes of the new book project, it’s also a delightful place to have lunch with one’s fellow river nerds.