Here’s an easy ramble in a beautiful place, suitable for little kids and for geezers like me. The route is simple: follow a two-track up a gently sloping canyon bottom, stop somewhere for lunch, and return the way you came. You can go a few hundred yards, or about four miles one way. The canyon bottom is a meadow, including wetlands. The flanking slopes are an eye-pleasing mix of conifers, aspens, and tuff outcrops. Best of all, there’s a live stream—a rare treat in New Mexico. It's name, Río Cebolla, no doubt refers to wild onions.

To get to the trailhead, head north on NM 4 from San Ysidro or west on that highway from Los Alamos. At La Cueva, turn onto NM 126 and wander north and west to the Seven Springs Hatchery. Turn right (northeast) onto Forest Road 314, leaving the pavement, and drive past the hatchery. FR 314 is graded and should be usable for passenger vehicles, if you’re careful about the rough spots. A little over a mile up the road, you’ll reach the Seven Springs picnic area (a fee area). Once at the loop you’ll find a pit toilet. You can park there or drive a couple of hundred meters farther up the canyon to the locked gate. 

The ramble follows FR 314 past the locked gate. This section of the valley is known as Oat Canyon. About a mile from the gate, you reach the section known as Hay Canyon. Here, FR 314 fords the Río Cebolla, but the stream is so narrow you should be able to find a spot to step across it. A half-mile farther on, you’ll reach McKinney Pond. If you keep going, eventually you’ll reach the point where FR 357 crosses the canyon. So far I’ve only gone as far as Oat Canyon, but hope to go farther the next time I’m there.

If you’re so inclined, you can fish this section of the Rio Cebolla for trout (the Red Chile Water—Native Trout Conservation rules apply). As with all wild water in New Mexico, purify the water before drinking it.