Before you travel, download our free travel app to explore the Hill Country

Midway between Fredericksburg and Comfort in the Texas Hill Country, you'll find Old Tunnel State Park . The park is a prime example of the blending of human and natural history, and offers an opportunity to visitors to see a unique and breathtaking natural display. Commerce and cargo used to pass through this railroad tunnel, but it's now home to some fascinating winged tenants.

Old Tunnel State Park

The advent of the railroad system redefined how Americans transported themselves and important supplies and commodities across this huge nation, starting in the early 1800s. The landscape changed as ribbons of steel made their way through the countryside, crossing rivers, mountains, valleys, and terrain of all kinds. The Lone Star State played its part in the growth of the railroads, and Old Tunnel State Park stands as a reminder of that chapter of our nation's history.

Once the dust had settled after the Civil War, city officials and business owners in the growing town of Fredericksburg wanted to establish a rail line between them and the larger city of San Antonio. Numerous delays created by both surveying and drumming up money for the line stalled its construction for several years, but in 1913 it opened as the San Antonio, Fredericksburg, and Northern Railway (the name of the railway was changed to the Fredericksburg and Northern Railway in 1917).

The Fredericksburg and Northern operated for almost 30 years; at one point, a tiny village called Cain City was founded as a stop between Fredericksburg and San Antonio. The rail line's history of operations was troubled from the beginning, however. During its construction, it was eventually discovered that a tunnel would need to be built in order to cross a steep change in elevation and challenging terrain. This ballooned the cost of construction, and over the years the profits from the line's operation were unable to overcome this debt. As a result, the line was abandoned in 1942, and the track was scrapped. Cain City became a ghost town, and the path where the tracks ran was eventually overtaken by natural growth.

As the years passed, the only remaining sign that the Fredericksburg and Northern had ever existed was its tunnel. The human inhabitants in the region had no use for it, but there were critters who came along who found it a perfect place to settle. Mexican free-tailed bats began to gather at the tunnel, until their numbers grew to over three million, and these days they call it home between May and October. Just to mix things up, 3,000 cave myotis bats have joined the colony, too. The 16 acres surrounding the tunnel were purchased by the Texas Parks and Wildlife Department in 1991, for the express purpose of protecting the bat colony. The state parks division took over the management of the area, and it officially became Old Tunnel State Park in 2012.

Old Tunnel State Park

Between late spring and early fall, the bats fly out of the tunnel to feed; the park calls this the Bat Emergence. The gigantic number of bats all come out at once, shifting upward in a counterclockwise direction, creating an undulating, dark curtain that fills the sunset sky. It's estimated that the colony here consumes over 25 tons of insects every night; when you consider what the average moth weighs, that's a mind-boggling amount of pest control! Observers may catch a full “circle of life” experience during the Bat Emergence, as well; natural predators such as red-tailed hawks and raccoons use this as feeding time, too, snacking on a bat or two as they come out. We all gotta eat, right?

The park features two viewing areas for the Bat Emergence. The upper viewing area offers more of a panoramic view, the Hill Country creating a beautiful natural backdrop as the bats make their way out. A more close-up view of the emergence is available at the lower viewing area, where the flapping of millions of bat wings often creates a breeze that wafts over the spectators below. Park rangers also conduct educational tours and lectures, sharing information and history about both the bats and the tunnel itself. Please note the upper viewing area has a guest limit of 30 people, and a maximum of 15 people can visit the lower viewing area at a time. For safety and noise regulation reasons, children under four are not allowed in the lower viewing area.

Old Tunnel State Park is also open for day use. There's a half-mile nature trail, where you can take a relaxing hike as you check out the park's daytime birds, wildlife, and plant life. Guests are asked not to wander from the officially designated trail, or toward the tunnel, during the day. Picnic tables are placed throughout the park for your convenience; however, you must provide your own drinking water. Restrooms at the park are open only during the evenings during bat season (May through October). Remember, the park's first priority is the preservation of the bat colony; for that reason, smoking, camping, and pets are not allowed on the grounds.

Chiroptophobia aside (that's a fear of bats; we had to look it up), the Old Tunnel State Park presents a stunning show for nature lovers, history buffs, and sightseers alike. Day or night, it's definitely an amazing spot to check out during your Hill Country vacation.

While you're adding Old Tunnel State Park to your itinerary, make it a point to contact us here at Backroads Reservations ! We'll help you maximize your Hill Country holiday with the most interesting, comfortable, and budget-friendly guest homes and cabins in the area.

Old Tunnel State Park is located at 10619 Old San Antonio Road, Fredericksburg, Texas 78624. The park itself does not have a phone, but visitors can call ahead for Bat Emergence information at (866) 978-2287. The park trail is open to day visitors seven days a week, all year long, from sunrise to 5 PM daily. From November to April—the period of time when the bats have migrated south to Mexico—the park is closed after 5 PM. Daytime admission to the park is free of charge to visitors of all ages. No pets, camping, or smoking are allowed on the park grounds at any time.

Bat Emergence observation is open to the public from May 1 to October 31, and tours begin approximately one hour before the bats come out. Admission to the upper viewing area is $2.00 per person, and $5.00 per person for the lower viewing area; these admission prices apply to visitors of all ages. The maximum people allowed in the upper viewing area is 30, and 15 for the lower viewing area. With these space restrictions in mind, interested visitors MUST get permits ahead of time online or by calling the State Parks Customer Service number at (512) 389-8920. No one will be admitted to the Bat Emergence viewing areas without a permit, and these permits can't be issued on-site at the park. Please also note that Texas State Park passes can't be used toward a Bat Emergence viewing.

Finally, please keep in mind that bats don't follow clocks like we do. Under certain weather conditions, they may decide to stay put inside the tunnel, or they may wait until past dark, at which time it's more difficult to see them. The park rangers do their very best to place visitors in the best bat-viewing locations at the best possible times, but they of course can't be responsible for bat behavior. Bat Emergence permits, therefore, can't be refunded if the bats aren't visible to observers.

Your visit to Old Tunnel State Park is just one of the many great attractions the Hill Country has to offer! Before your visit, take a few minutes to look over the following links to the great towns within an hour's drive of the park:

Bandera (41 miles southwest)
Boerne (29 miles southeast)
Comfort (13 miles southwest)
Fredericksburg (14 miles north)
Helotes (54 miles southeast)
Kerrville (31 miles west)
Medina (43 miles southwest)
Pipe Creek (44 miles southwest)
Tarpley (54 miles southwest)