As part of our goal to expand our Spring Seeker project into new sections of the Bavispe Flora and Fauna Protection Area, we recently had the opportunity to explore the Sierra San Diego for the first time — a sky island about two hours southeast of Douglas, Arizona. This expedition included staff from Sky Island Alliance and APFF Bavispe and its PROREST program, as well as biology students from the Universidad de la Sierra and environmental sciences engineering practicants from the Universidad de Sonora.
On the first day, we made our way to the campsite. Upon arriving, one of the first things that caught my attention was the beautiful view of the Rio Bavispe and, in the background, the Sierra Madre Occidental. It was one of those landscapes impossible not to admire — the kind that makes you pause, take it in, and give thanks for the wonders nature offers us. After setting up camp, we shared a delicious carne asada, because moments of connection are also part of our expeditions and a chance to get to know and learn from the experiences of everyone who takes part.
In the morning, we split into three teams to cover different survey routes. We were assigned one of the longer routes, and it was a demanding hike — but also one of the most memorable I’ve had. I really enjoyed the scenery and the company of my team. Something that surprised me was that we didn’t find as much surface water as I expected, even though the rains had already begun in some parts of the area. Along the way, we spotted plants like walnuts, maples, sycamores, and other species that typically indicate the presence of water. Even so, much of the streambed was dry, likely due to the drought and wildfires that have affected the area, reducing the aquifers’ capacity to recharge.
Additionally, much of the soil in the Sierra San Diego is made up of exposed rock, which limits rainwater infiltration and causes water to run off quickly into the Rio Bavispe. It’s precisely because of this scarcity that documenting these small springs — which sustain life in the area — becomes even more important. There we found mosses, ferns, grasses, and various plants adapted to living where moisture persists for much of the year. We also observed small snails, aquatic insects, and other organisms that depend entirely on these microhabitats to survive.
While walking, I nearly stepped on a black-tailed rattlesnake camouflaged among the rocks and leaves. Fortunately, I spotted it in time, and we stopped to take a few photos before letting it continue on its way. At one point, we rested inside a small cave in a high spot, where cool air flowed through. From there, we took in a beautiful view.
On the third day, we started very early with a beautiful sunrise. To begin the routes, we had to drive a bit higher up in the vehicles. That day we weren’t as lucky finding water, but we did come across a beautiful pygmy owl and we once again enjoyed the scenery of the Sierra San Diego.
On the last day, in the morning, we broke camp and began our trip back. Along the way, we had the chance to photograph an impressive collared lizard. It was wonderful to see, since I’d never before encountered one in the field.
On the way from Bavispe to Agua Prieta, we stopped to visit “El Caracol,” a site I had wanted to see for a long time. It was without a doubt a beautiful place that exceeded all my expectations — a true oasis where water bubbles up amid abundant wetland vegetation. We found leopard frogs, an Arizona alligator lizard, and a wide diversity of water-associated plants like the scarlet monkeyflower. We even spotted bats taking shelter in the deeper areas. It was truly the perfect ending to this great adventure.
We’d like to thank the staff of APFF Bavispe for granting us access to the Natural Protected Area to continue documenting springs, as well as the students from the Universidad de la Sierra and Universidad de Sonora, and everyone who made this expedition possible. Thank you for enduring the long hikes and sharing your enthusiasm, knowledge, and commitment to conservation.
