Texas' Smallest State Park Is An Under-The-Radar Escape With A Unique, Seasonal Wildlife Attraction

Rowdy wildlife, rugged hiking paths, untamed wilds, and beautiful views are pretty easy to come by in some of Texas' most underrated state parks. You can find a little of all the above in Old Tunnel State Park – an off-the-beaten-path escape situated about 60 miles northwest of San Antonio. We say little because the wilderness area is exactly that. Stretching across the Texas Hill Country for just over 16 acres, Old Tunnel is actually Texas' smallest state park, according to Texas Parks & Wildlife. Despite its compact size, the wildlife refuge has one really big draw: It serves as a seasonal refuge for a colony of about three million bats. 

Old Tunnel State Park is also huge in history, aptly named after an old railroad passage used by the San Antonio, Fredericksburg, and Northern Railway during the first half of the 20th century. The state park is perched right off the Old San Antonio Road, too. Also known as the King's Highway, the historic 17th century route connected Spanish missions across Texas and served as an important trade corridor for the region. The nature area is out in the boondocks but still within easy reach. The little hideaway is roughly an hour's drive away from the San Antonio International Airport (SAT) and only about 14 miles from Fredericksburg, one of America's friendliest cities with wineries and German flair.

The night flyers of Old Tunnel State Park rival the likes of Texas' most bat-filled cave at the Bracken Cave Preserve, also located just outside of San Antonio. The swarm of Mexican free-tailed and cave myotis bats took up residence in the park's railroad tunnel after the passage was decommissioned in the early 1940s. Carved through a limestone cliff, the old tunnel is quite the landmark, stretching through the rugged hill for more than 900 feet. "Mind Blowing — the tunnel is an engineering feat and just the sight of the bats will blow you away," one parkgoer shared on Tripadvisor. 

You can see the nocturnal creatures from May to October, when they migrate to the refuge to rest and raise their young. The bat season viewing window does change regularly, so be sure to check the state park's Facebook page for updates ahead of your visit. Old Tunnel State Park, which is open from sunup to 5 p.m., doesn't charge an entrance fee. However, if you want to stay after dusk to see the bats emerge, you will have to fork over a few bucks to access either of the two viewing areas. 

The upper overlook is the farthest away from the tunnel and costs $2, while the lower section sits right above the entrance and costs $5, at the time of writing. A few things to note: The lower viewing area is only available Thursdays to Sundays. Catching a glimpse of the bats is also not always guaranteed. Tickets often sell out fast, so be sure to snag them well in advance. And don't forget to bring a pair of binoculars to get a better view.

Whether or not you come for the bats, you can still enjoy a nice little ramble along Old Tunnel State Park's short nature trail. It spans about three quarters of a mile roundtrip and is dotted with interpretive signage about the region's railroad roots and, of course, the bats. "Great trail!! Great views. Easy to moderate hike. Recommend," one person wrote on AllTrails. However, in a Google review, another visitor warned that the stairs leading down to the path could be tricky for some, so be sure to watch your step. "Once you make it to the trail path, it is kept in very good condition," the hiker added. "One word of advice, do not make a lot of noise and you might get to see nature."

As you go, keep an eye out for other wildlife, such as foxes, deer, and various birds. There are grassy spots to plop down on if you want to tuck into a packed lunch along the way. The refuge also has a few picnic tables near the upper viewing area if you'd rather keep your grub off the ground. Respect the bats as you trek through the Texas wilds by keeping a safe distance from the tunnel. Since the state park is a nature-focused viewing site, pets are not allowed, so be sure to leave your pups at home. Smoking and drinking alcohol on the park grounds is also prohibited. Leave no trace and enjoy the view.