McKinney Falls State Park: Trails, Waterfalls & Volcano in Texas

McKinney Falls state Park, Texas

Updated July 2026

McKinney Falls State Park has remained one of our favorite day trips from the Austin area. Located less than 30 minutes from our home, it's the kind of place we find ourselves returning to again and again. Looking back through these photos from 2008 reminds me just how much there is to discover—from waterfalls and ancient volcanic rock to fossils, wildlife, fishing, and quiet trails shaded by towering cypress trees.

Walking Across an Ancient Volcano

One of the things that makes McKinney Falls State Park so unique is that you're actually walking across the remnants of an ancient volcano.

The waterfalls flow over rocks that were formed by the Pilot Knob volcanic field, a series of volcanoes that erupted roughly 80 million years ago, during the Late Cretaceous Period. At that time, much of Central Texas was covered by a shallow inland sea, and volcanic activity beneath the ocean helped create the unusual rock formations that visitors see today.

While the volcanoes have been extinct for millions of years, the hardened basalt and other volcanic rocks remain. These dark volcanic rocks are much less common in Central Texas, where limestone is the dominant landscape. That's one reason McKinney Falls looks so different from many other Texas parks. As Onion Creek has slowly carved its way through both volcanic rock and limestone over countless centuries, it created the beautiful waterfalls, pools, and sculpted rock ledges that make the park such a popular destination.

As we explored the creek, it was fascinating to think that beneath our feet lay the remains of an ancient volcanic landscape that existed long before people—or even dinosaurs had disappeared from the Earth.

Knowing that this area was once covered by an ancient sea made me pay closer attention to every rock beneath my feet. Between the volcanic formations, fossils, and unusual limestone, McKinney Falls feels as much like an outdoor geology museum as it does a state park.

On the spur, we decided to head for McKinney Falls state park. Might as well, as we wanted to get our money's worth on our state park pass. Also, McKinney Fall's happens to be practically in our backyard (less than 30 minutes away.)

Pilot Knob Volcano Lava

I hope you enjoy these photo's as much as I have. I tried to capture the beauty of this amazing area. The rock formations you see are molten lava rock from the Pilot Knob volcano - long ago extinct, but active thousands of years ago. (At least, we hope it's extinct. It rests near the Balcones Fault zone.)

overlooking Onion Creek

I'm no geologist by any stretch of the imagination, so bear with me. I'm also no photographer either, so just pretend you are seeing the park through my eyes, as imperfect as they are.

I found the thousands of puddles interesting in their own right. This one in particular showed me the simple beauty of nature and how life tends to grow and thrive under any circumstances.

McKinney Falls State Park is worth the visit

I kept my eyes glued to the ground, as we found flint and lots of interesting rocks and pebbles. Without a doubt, fossils and many other treasures are to be found... Alan and I have decided it's time to invest in a good metal detector to take on our trips...

Fishing at McKinney Falls

numerous water falls at the state park

There are several falls in the park. This one was located at the Homestead trail.

Stopping to smell the "roses"...

large trees at the park

The area consists of Bald Cypress trees, Sycamores and Pecan Trees... until you move further inland from the creek. Then there are various cedars, mesquite, etc. -- sort of like West Texas meets up with South Texas...

Cypress Tree

I found this tree stump fascinating. It was lying on its side and we marveled at how the pebbles filled its belly. (We had walked a long primitive trail past the falls along Onion Creek and found this stump.)

Indian Overhead - must see the visitor center!

Pamela, digging for sea shells. This area used to be home to the prehistoric reptile - Mosasaur - an entire skeleton had been found, along with various fossils, showing the area to have been a part of the shallow sea.

The Indian overhead was breathtakingly beautiful. Reminded me of our prior visit in Cedar Park to the Indian overhead that we had visited on CAVE DAY.

One of my favorite spots at the park - The Indian Overhead

It was a cool retreat from the warm sunshine and 80+ degrees...

Trees growing above the overhead

Plenty of shaded hiking trails at McKinney Falls

I gave up on capturing the height and width of this tree... Reminded me of those California Redwoods... well, at least a baby one.... (click to enlarge)

Spotting deer at the Texas state park

We saw white-tailed deer, Armadillo's, baby snakes, and dark scurrying shadows within the woods...

Struck by lightning?

Resting on the trails

McKinney Falls has beautiful hiking trails

trying our hand at fishing

Time to cast those lines...

This hole leads down into Onion Creek and where the falls are spilling... SPOOKY - not a place to slip and fall into!

These falls were located on the other side of the park, and where we decided to fish...

Someone caught a tree!

I couldn't help but notice that this was a favorite fishing spot. If you could see this tree with your own eyes, you'd realize that SEVERAL people had cast their lines WAY HIGH into the sky to snag these branches... Can you count how many bobbers and lures are in this tree? Now it looks like a Christmas tree...