I love when people ask me for hiking recommendations, but there’s one question that used to fill me with dismay: Is there a place where I can both hike and swim in San Antonio?

Unfortunately, our old and sprawling city does not have any swimmable creeks or rivers, mostly due to bacterial pollution tied to runoff from asphalt and concrete. My response was usually to direct people to Guadalupe River State Park or Canyon Lake, both roughly an hour’s drive from downtown.

That is, until I discovered Castroville Regional Park. It may not be in San Antonio, but it’s only a 30-minute drive west on U.S. Highway 90, and it’s got a lot to offer.

Castroville Regional Park

Offers: Hiking, swimming, camping.
Location: 816 Alsace Ave, Castroville, TX 78009 (24 miles from Main Plaza.)
Trail miles: 4.5 miles
Restrooms: Restrooms and potable water are available at the park.

On its 126 acres, the park boasts 4.5 miles of trails and a long section of Medina River frontage that’s perfect for swimming. Visitors can even rent RV and tent camping sites there to stay overnight.

This park became an oasis for me and some friends in August and September, when prolonged dry conditions had left most Hill Country rivers running low. Because Castroville lies downstream of Medina Lake, the Medina River’s flow in that area is much more reliable in dry times.

My first few visits centered entirely on the river, which has several beautiful swimming holes and sturdy rope swings tied to the cypress trees that provide ample shade. The river flows past picnic areas and barbecue grills, and it isn’t far from an expanse of grassy fields, perfect for kicking a soccer ball or tossing a Frisbee.

Castroville Regional Park has a series of swimming holes along the Medina River.
Castroville Regional Park has a series of swimming holes along the Medina River. Credit: Brendan Gibbons / San Antonio Report

Only on later trips did I find the network of hiking trails traversing the 126-acre park. I learned that these trails offer high-elevation vantage points that are rare for our region, including views of the beautiful town founded in the 1840s by mostly German-speaking Catholics from the Alsace region of France.

The Castroville community has done a good job explaining the park’s history via interpretive signs placed along these trails. I learned that, after the land was bought and sold by several farming families, it was the Hoog family that spurred the park’s creation in 1968. The story also explains why this park has a small wastewater treatment plant at its center.

Apparently, the growing town needed a modern plant to treat its sewage but could not afford any of the potentially suitable properties nearby. The Hoogs offered to sell the land for a fraction of its appraised value, with the understanding that the land not needed for the plant would be turned into a public park. The city opened the park in 1974.

Since then, volunteers have built and maintained a network of trails. These are for foot traffic only – no bicycles, motorized vehicles, or horses.

One interesting feature of the property is the irrigation canal that runs along its western edge. The canal is part of the more than 250-mile system maintained by the Bexar-Medina-Atascosa Water Control and Improvement District No. 1.

DO NOT attempt to swim in that canal. Irrigation canals can be extremely dangerous, with unpredictable, swift currents and steep banks that can be difficult to climb out of. Save the swimming for the river or the park’s swimming pool.

However, The Trailist recommends the 0.8-mile Canal Trail that parallels the irrigation channel as a place to see some of the best views in the area. It’s also teeming with wildlife. I saw plenty of hawks, deer, and songbirds as I traversed the area in late August.

The Canal Trail paralleling an irrigation channel at Castroville Regional Park.
The Canal Trail paralleling an irrigation channel at Castroville Regional Park. Credit: Brendan Gibbons / San Antonio Report

My favorite hiking loop I found at the park starts by following the 0.1-mile Creek Trail on the south end of the property up a ravine to the Canal Trail. From there, walk north along the Canal Trail, stopping at some of the seating areas built along that trail. Eventually, you’ll reach the 0.36-mile Rocky Ravine trail, which cuts across low brush to the trail that leads up Cross Hill.

At the intersection of Rocky Ravine and Cross Hill, it’s worth taking a left and ascending to the top of the hill, where a white-painted concrete cross marks the summit. From there, hikers can look down over much of Castroville and the broader Medina Valley.

After taking in the views, turn around and take the trail down to the parking lot on the north side of the park, then follow the gravel road along the west edge of the open field back to the starting point.

Brendan Gibbons

Brendan Gibbons

Brendan Gibbons is the San Antonio Report's environment and energy reporter.