Places We Protect

Fred and Loucille Dahmer Caddo Lake Preserve


Weeping cypress trees line a lake with bright red and orange leaves.
Caddo Lake These wetlands are made up of mixed bottomland hardwood forests and shallow bald cypress swamps. © Lynn McBride

Big Cypress Bayou and Caddo Lake are renowned for their ecological and recreational value.



Formed by Big Cypress Bayou, Caddo Lake—one of Texas' few natural lakes—and its wetlands are made up of mixed bottomland hardwood forests and shallow bald cypress swamps, covering more than 25,000 acres along the border of northeast Texas and northwest Louisiana. The region is one of only 27 wetlands in the United States recognized by the Ramsar Convention on Wetlands, an international treaty that recognizes exemplary wetland systems around the world.

The Nature Conservancy (TNC) became involved in efforts to conserve Caddo Lake in 1990 after receiving two land donations: 478 acres from local landowner Robert McCurdy and 589 acres from Judge John Paul Harkey. In 1997, this acreage was combined to create the preserve. Then in 2001, it was re-dedicated in memory of the late Fred and Loucille Dahmer, who lived at Taylor Island on Caddo Lake and spent much of their lives exploring, photographing and protecting its fragile habitat.

In 1993, TNC and Texas Parks and Wildlife Department joined forces to purchase 7,000 acres, which were added to the initial 483-acre Caddo Lake State Park, to create the Caddo Lake State Park and the Caddo Lake Wildlife Management Area we know today. After years of work, the U.S. Fish and Wildlife Service opened the Caddo Lake National Wildlife Refuge in 2009, further bolstering regional conservation efforts.




786 acres

Explore our work in Texas

Ebb & Flow (4:56) TNC has been involved in efforts to conserve Caddo Lake since the 1990s. Now, we're rethinking dam operations in the Big Cypress Bayou region to help restore river flows.
A cypress tree covered in moss hangs over a kayaker.
CRITICAL HABITAT TNC's Fred and Loucille Dahmer Caddo Lake Preserve is home to numerous endangered, threatened and rare species. © R.J. Hinkle

Why This Place Matters

Caddo Lake's wetlands are home to nearly 190 species of trees and shrubs, 93 different fish, 46 reptiles, 22 amphibians, 47 mammals and more than 20 mussel species. More than 220 species of birds, including dozens of neo-tropical migratory songbirds, find refuge here. The U.S. Fish and Wildlife Service has prioritized the area based on the high-quality habitat for migratory and resident waterfowl. Today, however, more than 40 of the native species at Caddo Lake and Big Cypress Bayou are endangered, threatened or rare. 

Big Cypress Bayou and Caddo Lake are also renowned for their recreational value, which helps fuel the local economy. Each year, the lake draws thousands of anglers and waterfowl hunters. Kayakers and canoeists can paddle through towering, moss-draped cypress trees, while wildlife watchers can search for hundreds of different species.

One of the major threats to the health of Caddo Lake is the growing presence of invasive plant species. While natural, seasonal flows can help with the management of these exotic plants, many non-native species are choking out native flora, like giant salvinia—a noxious, floating weed that can double in size every two to four days. Other troublesome invasive plants found here include hydrilla and water hyacinth.

Photos from Caddo Lake Preserve

Discover the diverse aquatic plant life and wildlife at this bald cypress swamp with bottomland hardwood forest.

Two kayakers paddle along an expanse of trees covered in low hanging moss.
A white bird with a yellow beak hunches down on a thin branch.
A series of trees with thick trunks and branches covered in Spanish moss tower over languid lake waters covered in lily pads.
An aerial view of forested wetlands.
Wide, stately tree trunks and branches covered in red, orange, and green foliage.
An owl stares straight at the camera with mottled, brown feathers and a white chest.
A cluster of trees sit on the edge of a lake as a red, orange, and purple sunset reflects off the water.
Two large trees shoot up from the misty waters of a tree lined lake at sunrise.
A man in a baseball cap stands in front of a lake, holding a fish with a lengthy snout.
A lone kayaker paddles between towering trees along a lake.
Two men examine a water sample pulled from a lake.
Flowing Waters TNC staff and partners examine a water sample from Caddo Lake. © Fauna Creative

What TNC Is Doing

When a dam was built upstream on Big Cypress Bayou to form the Lake O’ the Pines in 1959, plants and animals that had adapted over the millennia to the natural ebbs and flows of the bayou quickly found themselves at the mercy of the dam. Some flood and drought levels are important for fish spawning, cypress tree regeneration and the flushing of excess sediments and nutrients, which can negatively impact aquatic plants and animals. Without this seasonal variation of flows, wetland communities can become stressed. The management challenges at Big Cypress Bayou are exacerbated by a weir, or low-water dam, on Caddo Lake that prevents its drawdown during periods of drought. 

The Cypress Basin Flows Project was initiated in 2004 by a partnership between TNC, the U.S. Army Corps of EngineersCaddo Lake Institute, the Northeast Texas Municipal Water District and many other organizations. Further spurring the environmental flow work at Caddo Lake was a partnership between TNC and the Corps, called the Sustainable Rivers Project—a pilot project launched in 2002 to protect river ecosystems downstream of multiple dams in 13 states. So far, the project is demonstrating that science-guided changes to dam operations can improve river health while maintaining—or even increasing—other services, such as hydropower generation, water supplies and flood risk management. The project at Caddo Lake began after the State of Texas made the decision that no new water rights would be granted to protect the water flowing in our rivers, lakes and bays. The state enacted a law (Senate Bill 3) to provide a process for setting aside water for in-stream flows in Texas.

Working with the Corps and other partners, TNC defined the ecosystem flow needs of Big Cypress Bayou and the Caddo Lake wetlands through an initial study. Following this, several of our flow recommendations were implemented on an experimental basis from 2006 to 2011. At a December 2011 workshop, the partners agreed to implement many of these flow recommendations on a continual basis for the next five years, as permitted by drought and water development. Partners are also developing and implementing a monitoring plan to evaluate response to these new flows. Research is currently ongoing to help the Corps determine how healthy flows can be restored and the feasibility of modifying the weir dam at Caddo Lake while continuing to meet water supply and flood control obligations.


  • If you'd like to learn more about TNC's work with the Sustainable Rivers Project or our other freshwater initiatives, contact Director of Water and Science Ryan Smith (ryan_smith@TNC.ORG).

  • View a map of the Caddo Lake conservation area.