*Last entry is an hour before closing


*Last entry is an hour before closing

A Month in the Field in Baja California Sur: Part I

Dr. Sula Vanderplank, BRIT Biodiversity Explorer

Part I—“Bighorn Sheep Habitat, Sierra Tres Virgenes”

Colleagues: Dr. Alan Harper, Benjamin Wilder, Rodrigo Rentería

Guides and muleteers:

  • Jesus “Chuyito” Arce Ojeda and wife María Marcial Morales
  • Rafael “Falo” Lopez Arce
  • Ignacio “Nacho” Arce Arce
  • Juan Ojeda Arce
  • Guillermo “Memo” Ojeda Arce

Oct 21st, Day 1, Monday: ARRIVING

We woke up early, ready. We took a turbo prop from Los Angeles International Airport to the town of Loreto, the oldest town on the peninsula of Baja California, on the western coast of the Gulf of California (the Sea of Cortez). The vegetation looked lush and green and as the plane lowered, our spirits soared. We were delighted to be reunited with our friends and trip companions (after a brief panic when one friend arrived late!).

As we attempted to adjust to the embracing warmth of the post-hurricane summer, we ate lunch in the town with our friend Trudi Angel who is organizing the Mula Mil expedition (a mule trip leaving November 1st that will travel the whole length of the peninsula). The talk at lunch centered around the tragic news of a small plane that crashed in the hurricanes last week just north of our town.


We had a long drive ahead of us, and it turned out to be stunningly beautiful. As we wound our way along the coast, we looked out across forests of giant cacti or cardones (Pachycereus pringlei) and towards the sea, to the scattered islands sometimes referred to as Mexico’s Galapagos. Unable to resist temptation, we made two pit stops: one to look at some large temporary lakes that had formed at the side of the road and attracted many ducks, and a second to investigate a roadside population of desert passionflowers. We lost our convoy, but after a fairly serious detour, we found each other, arriving at the base of the Sierra de Las Tres Virgenes (mountain of the three virgins) – a volcanic range, home to the bighorn sheep. We were delighted to be united with our guides and muleteers, old friends and new friends, but all wonderful people. Suddenly we weren’t so tired, and we sat around the campfire hearing everyone’s latest news and talking about our previous trip to the region in April when we visited the Sierra San Francisco, home to the peninsula’s great cave paintings, thousands of years old and sometimes meters high on the steep cliffs above the dry waterways.

Volcán Tres Vírgenes at sunset (Copyright Alan Harper)

As always the company of our guides was refreshing to the soul. They are direct descendants of the first californios, the first European settlers to arrive and settle on the Baja California peninsula, their ancestors being the soldiers that accompanied the missionaries. The families that settled here have been self-sufficient for hundreds of years and live primarily off the land and their animals. (See “Corazon Vaquero,” an excellent documentary on their lives, for more information.) They are noble and charming people, honest, open, genuine, and as generous as the day is long. Eventually we made our way to our different tendidos or sleeping spots which varied from small tents to sleeping on horse blankets, to (in my case) climbing into a small boat or panga that was in storage under an open canopy and seemed like a great spot to lay out my sleeping bag with no fear of thorns or scorpions! The moon was enormous, and I went to sleep feeling absolutely delighted to be back in the heart of the peninsula.

Guides. Californios. Amigos.

Oct 22nd, Day 2, Tuesday: IN SEARCH OF BIGHORN SHEEP

Sunrise. The californios are a joy to wake up to, and I lay there listening to their friendly teasing of one another and general banter before dawn. Finally someone shook my arm. It may have been dark, but it was time to get up!

The coffee and breakfast started early, and the local oatmeal was soupy and delicious. It turns out our campsite was in a beautiful spot surrounded by large cacti, octotillos, and mesquite trees. Our guides do this for hunters that come here in search of the bighorn sheep. We, too, had come in search of the bighorn sheep, not to hunt, but to photograph, and to learn more about their habitat and the plants that can be found in these remote rocky outcrops of the peninsula.

It was 10:30 am before we finally drove to the end of the road and mounted the saddles of our mules. They are extremely well-behaved animals with comfy saddles. We rode ahead while two muleteers continued to pack our food and sleeping gear onto a team of donkeys. The first stretch of the trail was open and beautiful and fairly flat, slowly gaining altitude until we turned a bend and caught sight of the marvelous view of the extensive valley below. I hadn’t realized how high we had climbed so quickly.

View from Volcán Tres Vírgenes of the valley below. The Sea of Cortez is in the background.

We stopped to photograph a beautiful specimen of the local cactus Echinocereus brandegeei and then continued our way up the hot dusty path, everyone with big hats or sombreros. Soon we could see the ocean, and it was hard to want to keep going and not start looking at flowers! We were assured that soon we would reach the saddle where we were to camp… and surely enough, we turned a corner in the path and saw before us a spectacular flat area that would be our base camp.

Echinocereus brandegeei

We had reached the base of a giant forest of sotol or Nolina palmeri var. brandegeei, a plant found only in this region of the peninsula and reaching 5 m high here on the steep, northeastern slopes leading to the three-pointed peak. Our first bighorn sheep was spotted through binoculars on the adjacent mountain. My friend and colleague Ben Wilder from the University of California-Riverside was far too excited about the plants to wait long for the sheep. So we set-off up into the bear-grass, and as we raced up the slope we found several plants far more common in the north, species we consider to be “chaparral” plants like Malosma laurina and Rhus ovata, which represent “sky islands” of plants left behind in small refuges in the mountains from a time when the peninsula was cooler, perhaps a little wetter, and the vegetation was less arid, and now clings to these small, less exposed outcrops.

Forest of sotol (Nolina palmeri var. brandegeei) (copyright Alan Harper)

We collected herbarium specimens of many beautiful species including a bright-red morning glory vine and three beautiful buckwheats (Eriogonum spp.). We pressed plants until dark, making specimens for BRIT, the University of Arizona, the San Diego Natural History Museum, and others, and then had a delicious campfire dinner of bistek beef with chilis, potatoes, tomatoes, and beans with tortillas. Later we sipped bacanora, a Sonoran mescal, under a sky glittering with stars, listening to the constant song of the crickets.

Gotta get ‘em in the press before they shrivel up! At least Ben, Maria, and Sula can sit while they press… (copyright Alan Harper)

Oct 23rd, Day 3, Wednesday: THE SUMMIT

To my surprise, today was to be a day on foot. We rose before dawn, ate a healthy breakfast of chorizo and eggs, and set off walking to the summit of the mountain. I had only packed for riding – heavy jeans, boots, large saddle bags, and no backpack! So I cobbled together some essentials in a portable field herbarium press that converts into a rather uncomfortable backpack, tied a water bottle to the cord of the camera around my neck, packed my belt with the radio and satellite phone, and set off up the gravelly slope eating the dust of those ahead of me.

It was a hard steep climb, but luckily every extra 20 m seemed full of botanical treasures to keep us from thinking about the heat and the thirst and the weight on our backs. Above the bear-grass forest we found what can only be described as a patch of scrub-oak woodland, with many large shrubs that I instantly recognized from our more Mediterranean climate to the north: the silk-tassel tree (Garrya sp.), scrub oaks (Quercus ajoensis), California lilacs (Ceanothus spp.), mission manzanita (Xylococcus bicolor), and a wealth of unexpected ferns hiding in crevices in the rocks of the understory. This pocket of vegetation is presumed to be left behind from a Pleistocene climate, giving us insight into what the vegetation of the whole region may have looked like in times gone by. Perhaps the biggest plant surprise was the carpet of alumroot (Heuchera), which made for stunning scenes of pink, interspersed with bright clumps of yellow sunflower relatives. Ben and I held back with one of our guides, Falo, who patiently waited for us each time we stopped to collect plants, and took us up the subtle trail to the peak.

Far ahead, friend and colleague Rodrigo Renteria, a Ph.D. student from the University of Arizona, had carried a telescope with him in attempt to locate more bighorn sheep. Rodrigo is an anthropologist who studies the social impacts of conservation and has done a lot of research on the impact of the bighorn sheep introduction on Tiburon Island (in the Sea of Cortez) on the indigenous Seri community. Here he contrasts the impact of the bighorn hunting on the ejido of Santa Martha – the californio community with whom we travel. Bighorn hunting is a big subject on the peninsula at the moment as the state of Baja California moves to open a similar program in the northern state for the first time. Each hunting tag sold generates a lot of money for the local community as well as the government, and the investment in maintaining a healthy sheep population for hunters does a lot to conserve wildlands on the peninsula. Our colleague Alan Harper, who is writing a book on the natural history of the peninsula, was also off ahead, looking to photograph the elusive sheep for his book.

Chuy sacrificing his body scanning for bighorn sheep. (Copyright Alan Harper)

After several hours of climbing we were all re-united at the summit (over 2,000 m in elevation), and rested in the shade to eat some snacks. A cell phone tower on a peak below gave us a few moments of contact with the outside world (which was not welcomed by everyone!). We were low on water, but spirits were high. We even found a signature book at the summit and signed our names before starting the long dusty descent. We pressed plants by headlamp late into the night and warmed ourselves with a mixture of rum and lemon juice.

Oct 24th, Day 4, Thursday: WATER SHORTAGE

It’s been hot, a lot hotter than we expected. There’s been no water for the mules for days, and now we humans were almost out of water. Luckily we had some stashed in the cars, and two of our guides (Juan and Memo) decided to go down to the road for more water, and I decided to go with them to collect plants at lower elevation and stay out of the way of those looking for sheep. The saddle came loose on my mule six times on the way down the mountain. Each time we stopped and got down and remounted the saddle…

Mules: we’d be toast without them.

It’s a lot drier at lower elevations and the pickings were slimmer in the plant world but included some fabulous mistletoes, including a bright red-flowered species called toji (Psittacanthus sonorae) that was parasitizing the fleshy purple tree torote (Bursera microphylla). As we dropped down the mountain away from the chaparral island at the top, the vegetation was again familiar to our guides and they were a wealth of knowledge on the local names and uses. For example, the bark of torote can be used to tan leather with a distinctive red tint. There were many medicinal species, too, and I did my best to jot down the information as we traveled.

A red mistletoe called toji (Psittacanthus sonorae).

As we started our way back up the mountain with the supplies the group was coming down. The water had run out hours ago and so the plans had changed. We were headed back down to a base camp that has a spring nearby where they might have one last chance of spotting a sheep in the morning. Arriving at the cars I stayed with the guides, and we drove the mules and donkeys down the road to the base camp. It was an exhilarating experience, and we made an impressive pace, arriving shortly after the vehicles. A giant pile of cactus wood had been stacked next to the firepit, and the light flickered through the holes in their skeletons as they burned. Our last night together was warm and friendly and involved a lot of singing around the campfire. The piercing voices of the guides had an inexplicable romance as they sang of lost loves and world travels.

A nice last night by the campfire. (Copyright Alan Harper)

Oct 25th, Day 5, Friday: SAYING GOODBYE

A small crew set out before dawn to look for bighorn while I stayed at camp to pack up. There were a lot of belongings to separate and retrieve from saddlebags, etc. We went to a neighboring ranch to get more water, and there they were preparing machaca, the dried salted beef we’d been eating for lunch each day.

The making of machaca, dried salted beef.

We said our goodbyes late morning. My eyes stinging with tears, I wished I could stay, but with the car packed to the limits we began the drive south. It was a travel day—we talked about future projects and collaborations as we headed for the next leg of our adventure. We were all glad to check-in with loved ones again by telephone. Since it had been five days since our last shower, we stopped and took a quick swim in the sea at the side of the road. The water was very salty and the sharp rocks cut my hands and hurt my feet, but it was well worth it and felt great to rid ourselves of the grime that had built up all over our bodies. The landscape looked a lot drier than on our way north, and we didn’t get to make any collections today. We’re tired, and it’s still a long way to the next leg of our expedition.


We had an exciting breakfast pouring over maps with friends and colleagues. Already planning future expeditions, we made lists of places that must be botanized, have never been botanized, and should be botanized, and then we attempted to start prioritizing. We are now with botanists Jon Rebman and John LaGrange from San Diego Natural History Museum and heading south to the start of the museum’s Binational Expedition to the Sierra Cacachila. Jon recently published a Field Guide to the Flora of Baja California and has invited me along as his field assistant.

We made our way to the great Magdalena plain to an area called llanos de hiray, which is home to some giant seasonally inundated pools that can receive summer or winter rain. We crossed huge agricultural fields and a lot of heavily grazed areas, but the natural vegetation was beautiful and we even caught a glimpse of Santa Margarita Island as we headed across the plain. The plain is not a hospitable environment for most species because the inundations create difficult growing conditions. As a result, the large low open area was home to just a handful of species including the enigmatic Burroughsia/Lippia fastigiata, a very restricted species in the Verbena family.

As we stopped at some of the areas where water was still standing, we realized that the pools were teaming with life and had lots of small crustaceans in them. We had a muddy time fishing out the freshwater arthropods for photographs—one looked like a miniature horse-shoe crab! To add to our delight at this spot, we found the unusual sporocarp-bearing fern Marsilea vestita. We only found a few plants, along the margins of the water, but this added to the wealth of unusual herbarium specimens collected today. Although these plants on the plains were not very diverse, they are often very special (either restricted or unusual in their survival strategy). This ecosystem is little-explored and little-documented and would be well worth a longer visit in future.

A horseshoe-crab-like wee one from the pools at llanos de hiray.

On slightly higher ground we were surrounded by insects: butterflies mobbed the bright yellow flowers of the Sonoran golden bush (Xylothamnia diffusa), striped native bees visited the flowers of the pink cactus Cylindropuntia cholla, and a big green spider hid in the branches of a ragweed (Ambrosia confertiflora).

Spider on Ambrosia confertiflora; native bee on Cylindropuntia cholla; butterfly on Xylothamnia diffusa​​​​​​

As the light faded we headed south. The sunset was stunning across the forests of succulent plants and trees, and the traffic of La Paz was a culture shock as we pulled into the city. A kindly lad at the hotel had washed my clothes while I was eating dinner. I find myself pining for the mountain, for the soft songs of the muleteers, the open space, and the stars. I’m not enjoying being back in the city at all.

Stay tuned for more “Notes From the Field” from Dr. Vanderplank!

Top to bottom, left to right: Rodrigo Renteria-Valencia by the campfire; camp visitor (kangaroo rat); bringing the animals to camp; Volcan Tres Virgenes; summit ascent; scrub; wet area (all photos copyright Alan Harper)

Related Articles

Ruella strepens (smooth ruellia)

What Is This Thing? Smooth Ruellia and Why Some Plants Preferred Closed Marriages

Botanists and horticulturists love a challenge. That’s why this year we’re introducing a new feature in the newsletter: What Is This Thing? This month, Martha L. of Fort Worth asks us to identify a plant with small flowers than never open. The answer tells a fascinating story about the reproductive strategies of plants–and why some prefer closed to open marriages.

Read More »
BRIT Library

Botanical Art = Botanical Science

The history of civilization can be told through pictures of plants. The roots of botanical art and the science of botany began in ancient Greek and Roman times, depicting plants as a means of understanding and recording their potential uses.

Read More »
Collections Lens

Sean Lahmeyer of the Huntington Herbarium

As part of the Library’s Collection Lens series, BRIT Librarian, Brandy Watts, interviews Sean Lahmeyer of the Huntington Herbarium who discusses the history of the collection and its growth through the years.

Read More »
BRIT Research

National DNA Day

A Peek Inside Sumner Lab on National DNA Day Lab Volunteer, Jerrod Stone, shares his experience and the latest projects April 26th is National DNA

Read More »