Baca Ranch in Colorado
Baca Ranch A view across the Baca National Wildlife Refuge at sunset with the Sangre de Cristo mountains in the background, Colorado USA. © Nick Hall

Places We Protect

San Luis Valley Baca Ranch


A haven for more than 70 species of rare plants and animals.

Why TNC Selected this Site

The San Luis Valley, nestled between the Sangre de Cristo and the San Juan mountains, represents one of the largest and most important natural areas in Colorado. Due to surrounding geology, the Valley is uniquely sheltered and remains in a relatively intact, natural state. Spanning 9,000 square miles—roughly the size of Connecticut—the San Luis Valley is home to the tallest sand dunes in North America, vast wetlands and a rich aquifer that sustains the plants, animals and communities that live there.

The Baca Ranch

The 97,000-acre Baca Ranch lies within the San Luis Valley and adjacent to TNC's Zapata Ranch and the Great Sand Dunes National Park. The ranch contains significant natural values including interdunal wetlands, sand dunes, shrublands and high-elevation forests. Its wetlands provide habitat for migrating waterfowl and the dunes are home to eight insect species found nowhere else on Earth. The ranch's water resources support the creation and replenishment of the dunes system. More than 70 species of rare plants and animals are found here, including several species found nowhere else in the world. The landscape provides vital habitat for a wealth of wildlife species, including a large elk herd, fox, mountain lion, bighorn sheep and numerous migratory bird species, including sandhill cranes.


One of the most significant features of the Baca Ranch is the aquifer that lies beneath the landscape. Though the Valley receives less than 14 inches of rain per year, mountain snowmelt replenishes this rich underground aquifer. This aquifer sustains the ranching and farming community and also supports the unique plants, animals and ecosystems—including the Great Sand Dunes—that thrive in this semi-arid climate. Plans to export water from the San Luis Valley to support other areas in the West have become a threat to this region. 

Our Conservation Strategy

The Nature Conservancy is working with State and Federal partners to institute a boundary-less framework for the entire Great Sand Dunes 500-square-mile complex to preserve native wildlife for future generations. We will continue to work in partnership with the local community, state and federal agencies, landowners and individuals to protect this biologically rich landscape and manage the water resources it supports.

What TNC Has Done/Is Doing

In 2002, after many years of hard work and collaboration, The Nature Conservancy signed a purchase agreement for the Baca Ranch. The acquisition of the ranch was the first step in a series of transactions. At $31.28 million, the Baca Ranch acquisition was the largest and most complex deal for the Conservancy in the Rocky Mountain West. It stands as a testament to the value of partnerships. The Nature Conservancy worked with political leaders, public and private agencies, foundations, local constituents and individuals to protect this sprawling wilderness.

In January 2003, one of the remaining hurdles in The Nature Conservancy's efforts to acquire the title to the Baca Ranch was overcome. An arbitration award was issued in favor of Cabeza de Vaca Land and Cattle Company, LLC regarding the value of the water rights associated with the Baca Ranch.

In September 2004, after more than a decade of work, TNC completed the last of a complex set of real estate transactions, clearing the way for the protection of the ranch and the designation of the nation’s 58th national park, the Great Sand Dunes National Park.

Upon closing the Baca Ranch transaction, TNC transferred management responsibility for 27,000 acres of land within the designated national park boundaries to the National Park Service. TNC continues to manage the remainder of the Baca lands in partnership with the U.S. Department of the Interior pending a final $3.4 million federal appropriation. Once the remaining monies are appropriated, the full ownership of the ranch will be transferred to the National Park Service, the U.S. Fish and Wildlife Service and USDA Forest Service to create the Baca National Wildlife Refuge and expand the existing Rio Grande National Forest.