Anza-Borrego's Desert Bighorn Sheep

Last Refuge of the Bighorn

3-Part Series Part 1

By Mark Jorgensen


Bighorn Sheep

Anza-Borrego is one of the last refuges of the Peninsular Bighorn Sheep. Only 280 of this subspecies remain in the United States and 200 find refuge in the park. Anza-Borrego is important to the Bighorn when you consider the explosive metropolitan growth of Southern California.

The park has an ongoing program to help the bighorn. Over a quarter of million dollars has been spent to improve bighorn habitat. Projects include construction of six water sources in the Vallecito Mountains, fencing of the park boundary to exclude trespassing cattle, the live removal of wild cattle from many of the west side canyons, and removal of exotic trees from desert water holes.


The Desert Bighorn has lived in the Borrego Desert for thousands of years. Bighorn migrated from Siberia over 10,000 years ago, extending their range throughout western North America. Today, Bighorn still range into Baja California, but their numbers have dwindled to less than three percent of the estimated 1.5 million of the early 1 800s. Human activities are responsible for the Bighorn's decline. Grazing, mining, depletion of water holes, homesteading, and use as camp meat spelled disaster for the Bighorn. Today their future rests in our hands. We can help them survive or let them dwindle into history. Hopefully, human concern will help in making their future look brighter.

Life Cycle

Visiting the park in fall, you may be fortunate to find Bighorn close to campgrounds and roadways This is the mating period when the large rams, carrying their huge horns proudly, seek out the ewes. The animals may appear bold at this time, making you wonder about their reputation for being wary and hard to see. Sheep have recently been seen in the middle of the road on Yaqui Pass and bedded down within 50 feet of Montezuma Grade. It seems the mating season is a time when Bighorn worry less about humans and predators and more about finding a mate.

baby bighornLambs are born six months after mating occurs. Most are born near steep cliffs from late February to May. Only about one-third will survive their first summer. An animal born late in the season stands little chance of survival, since temperatures reach over 100 degrees F in May and often reach 120 F by June. Recent studies of high lamb death rates focus on viruses possibly introduced by domestic livestock, to which the native Bighorn have little or no immunity. Studies continue, and the park has done everything possible to remove feral livestock and to keep Bighorn habitat free of trespassing cattle and goats.

Ewes are protective of their young for many months. Yearlings, often abandoned while the ewe is giving birth to her next lamb, may be seen again with the ewe and lamb late in the spring. Bighorn find safety in Coyotenumbers and are ever watchful for predators such as Coyotes and Mountain Lions. In a recent three-year period, Mountain Lions were documented taking over 40 radio-collared Bighorn Sheep in Anza-Borrego. Ewe horns are about ten to fifteen inches long and their sharp tips are effective protection against Coyotes.

When a lamb is sick and pneumonia renders it helpless, Coyotes become superb predators. The ewe must abandon the lamb and head for the steep slopes and safety. All too often researchers or hikers find the carcass of a dead lamb near a water hole.

The Future

To maintain a sheep population, about 25% of the season's lambs should survive. The Vallecito group has maintained a population of about 30. The Coyote Canyon group is declining due to Mountain Lions. The Palm/ Tubb, and the Southern Santa Rosa groups seem to be holding, with the loss of a few to Mountain Lions.

An alarming decline has been occurring in the southern end of the park. In Carrizo Gorge, we have documented a drop from about 120 sheep in 1972 to less that 40. Off-road vehicles, trespassing cattle, poaching in the 1960s and early '70s, drought, disease and Mountain Lion predation have worked together to push this population to the edge. We hope we can save this group before it is too late.

The "Borrego Cimarron" (as it was called by Spanish explorers) lent its name to this park, and we are dedicated to providing a lasting refuge for its future. These are challenging times in the recovery of Desert Bighorn in California. The future of the Bighorn is in our hands and with your help we're proud to say we're doing something about it.

Go to: Last Refuge of the Desert Bighorn Sheep (2 of 3)
Go to: Last Rites for a Desert Bighorn (3 of 3)

Where to find them. Bighorn Sheep Watching

Video available on this subject.Movies
We have a short video on the Bighorn.

Have you checked out our Bighorn sheep for your home? Click Here

Bighorn Sheep Watching
Anza-Borrego Desert State Park
Bighorn Sheep
Desert Animals & Wildlife Index

Text: Copyright Anza-Borrego Desert State Park
Photographs and HTML: Copyright



Share this page on Facebook:

DesertUSA Newsletter -- We send articles on hiking, camping and places to explore, as well as animals, wildflower reports, plant information and much more. Sign up below or read more about the DesertUSA newsletter here. (It's Free.)

The Desert Environment
The North American Deserts
Desert Geological Terms



Desert Videos

Mountain Lion

The Mountain Lion Video
The Mountain Lion, also known as the Cougar, Panther or Puma, is the most widely distributed cat in the Americas. It is unspotted -- tawny-colored above overlaid with buff below. It has a small head and small, rounded, black-tipped ears. Watch one in this video.

The Black Widow SpiderView Video about The Black Widow Spider. The female black widow spider is the most venomous spider in North America, but it seldom causes death to humans, because it only injects a very small amount of poison when it bites. Click here to view video.

The Rattlesnake

The Rattlesnake Video
Rattlesnakes come in 16 distinct varieties. There are numerous subspecies and color variations, but they are all positively identified by the jointed rattles on the tail. Take a look at a few of them, and listen to their rattle!


Take a look at our Animals index page to find information about all kinds of birds, snakes, mammals, spiders and more!

Hot temperatures in the desertAre you interested in the temperatures in the desert?

Click here to see current desert temperatures!

Copyright © 1996- and Digital West Media, Inc. - -