Sheep arrive at Cronan Ranch to graze on invasive plants and reduce wildfire threat


Bureau of Land Management

BLM Office:

Mother Lode Field Office

Media Contact:

a herd of sheep in a green field

EL DORADO HILLS, Calif. – A flock of nearly 900 sheep have arrived at the Bureau of Land Management’s Cronan Ranch to start their summer of reducing wildfire threat by grazing on troublesome yellow starthistle and medusahead plants. A sheep herder will manage the flock, moving them across 1,000 acres with assistance from herding dogs and a livestock protection dog. The sheep will be removed at the end of August. 

“This is the seventh year that we have used sheep to control yellow starthistle and medusahead, both invasive weeds, that crowd out native plants and reduce the diversity of vegetation,” said Elizabeth Meyer-Shields, manager of the BLM Mother Lode Field Office. “Our monitoring has shown that carefully managed sheep grazing has dramatically reduced weed thatch and yellow starthistle.”  

The sheep help the Bureau of Land Management accomplish two important goals: ensure the health and safety of public lands through hazardous fuels reduction; and improve rangeland health by removing or preventing the spread of invasive plants species.

After six years of grazing, vegetation monitoring has shown a marked decrease in yellow starthistle and a notable decrease in medusahead. These invasive weeds leave behind dense patches of thatch, or dead vegetation, which can contribute to wildfire spread. Grazing has also dramatically decreased the thatch, reducing fuel loading and the risk of wildfire. In addition, native species diversity has increased, and wildflowers are blooming across the recreation area this spring, including some that have not been seen on the ranch before.

Know Before You Go:

The Cronan Ranch Trailhead provides access to 12 miles of trails for non-motorized uses including hiking, biking, horseback riding, fishing, bird watching and other recreation. There is a wide variety of terrain to explore including gentle slopes, challenging hill climbs, oak woodlands and gentle riverfront trails. Cronan Ranch connects to the American River Trail Corridor. More information is available at

Recreate Responsibly:

The BLM encourages the public to recreate responsibly on public lands and take precautions by adhering to posted grazing signs. Specifically, when sheep are present, please avoid conflict with sheep and dog(s) by stopping and dismounting if mountain biking, put your bike between you and the sheep and/or dog(s), walk your bike until you are well past the sheep, keep your distance from the flock, keep your dog(s) leashed at all times, watch for the protection dog(s) and the herder, and remain calm and quiet if dog(s) or sheep approach. 

The BLM manages more than 245 million acres of public land located primarily in 12 western states, including Alaska, on behalf of the American people. The BLM also administers 700 million acres of sub-surface mineral estate throughout the nation. Our mission is to sustain the health, diversity, and productivity of America’s public lands for the use and enjoyment of present and future generations.