In the Rio Grande Valley, the mighty river has shaped the land.  

The Rio Grande has repeatedly shifted course over the centuries, leaving behind remnants in the form of old channels. These former distributaries, called resacas, can look like rivers or lakes. Resaca de la Palma State Park in Brownsville offers one of the best chances to see resacas in their natural state.

The park’s resacas nurture the region’s native plants and animals — some of which are found nowhere else in the U.S.

Resaca de la Palma’s Ebony Trail provides a peek into this world.

The quarter-mile trail curves through old-growth ebony-anacua woodlands, considered one of the most threatened plant communities in the United States. The trail starts at the visitors center and ends at an observation deck overlooking a resaca, with signs along the way explaining the unusual plant life.

Superintendent Kelly Malkowski likes the Ebony Trail as an introduction to the region’s plants and animals.

“The Ebony Trail takes you through some special habitat,” she says. “The ebony-anacua woodland is some of the rarest habitat on the planet. It occurs only in the Rio Grande Valley, and there are very few remnants left. There are also good wildlife opportunities along the way.”

Along the trail, chachalacas squawk in the forest, green jays perch on limbs and Mexican bluewings flit about.

The thorny plants offer great shelter for birds and provide fruit for them to eat.

The park, part of the World Birding Center network, attracts migratory birds and is home to local specialties such as the groove-billed ani and Altamira oriole.

“These trees are like the ‘mother habitat,’” Malkowski says. “They’re good baseline plants for a healthy ecosystem. They have a lot of cultural significance, too.”

At the end of the trail, decks and a short boardwalk overlook a resaca, which can be wet or dry depending on the season.

“The resacas fill up and dry down,” she says. “We manage them and try to mimic their natural historical patterns.”