Cooley's Mammoth Jackstock

 Article written by Beth Cooley Newton for We Ride Sport and Trail Magazine, July 2017

Our farm, Cooley's Mammoth Jackstock, is located in Wagram in the North Carolina Sandhills of Scotland County.  We are located about twenty miles north of the North Carolina/South Carolina border.  We are a breeding farm for American Mammoth Jackstock.  Since 1998 John Cooley, the owner and operator, has researched, traveled and looked far and wide for specific foundation bloodlines and body types for selective breeding and has attempted quite successfully to build one of the best American Mammoth Jackstock breeding programs.

   A heritage breed is a traditional livestock type raised by our forefathers in the United States.  The American Mammoth Jackstock is a unique heritage breed of large donkey going back to the late 1700's, created to be used to breed superior mules by crossing the large males, called Jacks, with mares (horse).  Horses have 64 chromosomes, Mammoths have 62 and Mules have 63, which is why Mules are sterile and cannot reproduce.  Mammoths were developed in the United States from imported European breeds mixed with our native stock left here by the earlier Spanish explorers. George Washington was one of the first breeders of American Mammoth Jackstock using a jack gifted to him by the King of Spain who he named Royal Gift.  The Livestock Conservatory now has the American Mammoth Jackstock listed as an endangered Heritage breed.  I believe that there are less than 3000 American Mammoths in the world.  We know that Jackstock breeders selectively breeding for quality mammoths with foundation bloodlines are becoming just as rare.

Mammoths come in many colors black, gray, and sorrels (red). Here at Cooley's Mammoth Jackstock we only breed for black with white points and grays.  The American Mammoth Jackstock is the largest size of donkey and is known for being easy going, intelligent and deeply affectionate towards people.  Mammoths should be at least 58" (14.2 hands) at the withers for a jack (male) or 56" (14 hands) for a jenny (female) and have good bone density according to the AMJS registry.  Mammoths are truly the gentle giants of the donkey world.  Here on our farm we have adult mammoths ranging from 14.1 hands to 16.2 hands and weighing between 900 to 1200 pounds.  Mammoths are slow to mature and are not full grown until six years old.  Some of our Mammoths have grown as much as three to six inches in their third year.  Mammoths can live to be forty years old.

Our goal, here at Cooley's Mammoth Jackstock, is to breed a sweet natured, intelligent, forward moving, athletic American Mammoth Jackstock with balanced conformation with good bone density using foundation bloodlines.  We have some of the best old foundation bloodlines to be found anywhere; going back to PCF's Preacher, Rancho La Burrada Walter, Bully Boy, Jen Jack, 3 Jumps Big Louie and Siemon's Glen.  We sell our stock all over the United States, Canada and Mexico.

I'm Beth Cooley Newton; I assist John Cooley with all internet services (website, Face Book), sales, record keeping and helping with the jackstock.  I am constantly taking pictures of our mammoths and posting them on our website and face book pages.  John and I have been friends and neighbors for over twenty years.  About three and half years ago I began to help with the Mammoths as my horses had passed on.  I noticed immediately that being out in the pasture helping John with the Jennies that the “calm” came back to me that I have always had around the horses.  After being involved with quarter horses my whole life, I have gone to the "Donkey Side".  Mammoths are addictive and just like a potato chip, "One is not enough".

I began helping John do night watches with the pregnant Jennies and calling in John when they began foaling.  Gestation for a mammoth jenny is 12 months and some go 13 months.  We try to be present at all the births; our live birth rate has definitely improved since we have started doing this.  We believe in imprinting the babies the first few days after they are born touching them all over, picking up feet, haltering, leading, etc.  The babies never forget and are easy to handle and well behaved.

On April 22, 2016, I became the mama to a baby jack, Deacon, when his birth mama wouldn't accept him. It took John, my daughter, Jessi Newton and myself many hours but Deacon was raised on a bottle and I spent countless hours getting him socialized with the other mammoth babies, so that he knew he was a mammoth.  As a yearling, Deacon is an outstanding specimen of a mammoth jack with his true black coat with the white points. We show him quite successfully at halter and one day he will become one of our breeding jacks.

We have four breeding Jacks we use with our fourteen breeding Jennies.  Bainbridge's Long Ears Acres Black Cole (15.1 hands), CMJS Slate (15.2 hands), Coyote Lane Rhett Butler (15.3 hands), and CMJS Hank (16 hands).  We have quite a few Jennies that are 15+ hands and a few that are 16 hands.  We have forty mammoths on our farm and always have several for sale.

Mammoths are the strongest animals I have ever worked with; their strength and gentle nature is amazing.  They are used in many ways: companionship, riding, driving and we run ours with our cattle.  Mammoths tend to not like canines, especially coyotes, and are very protective of the herd.  It is possible to have dogs as we do and they can exist together.  Not much goes on around their pasture that those ears don't pick up on.  Mammoths tend not to bolt in fright as horses do, they stop and think about the situation before deciding to run or fight.  Once you have a mammoth's trust they will do anything to please you and are easy to train.  Do not make the mistake of thinking a Mammoth isn’t as quick as a horse because they are. Mammoths are growing in popularity because of their “laid back” attitudes and their surefootedness on the trail; they make great trail riding mounts.

Mammoths are special animals and extremely addictive, as you spend time with them they will fascinate you with their sweet disposition, intelligence, mischievous humor and personalities.  Mammoths love to be loved on and they give just as much affection back.  They hug you with their bodies and rest their heads on your shoulder. Their warm eyes tell you of their intelligence as they look you in the eye.

You can go spend time with them and they are the best stress relievers around.  They can put your world back in balance and bring calmness back to your inner self.  Plus you gotta love their long ears and then there is the Bray.....there is not another sound like it!

If you are interested in our mammoths, please contact us and we will be glad to answer your questions.   Visitors are welcome.

For more information visit our website:

Face Book pages: Cooley's Mammoth Jackstock and J Cooley Mammoth

or email us at


Written by Beth Cooley Newton for We Ride Sport and Trail Magazine, July 2017