Sometimes it takes a relative from out of state to make you aware of something pretty incredible that's right in your own backyard. That's exactly what happened over the 4th of July weekend when family members from Texas told me about the biggest standalone rock I believe I've ever seen... in Marion.

It's known as Waldo's Rock and is what's known as a glacial erratic. So what is that exactly? Wikipedia says it's a "glacially deposited rock differing from the size and type of rock native to the area in which it rests." I'd estimate the rock is at least 12-feet tall. It's believed to be the largest glacial erratic in the state of Iowa, south of Highway 20.

According to a sign at the Marion park that houses the ginormous rock, it's made up mostly of quartz and feldspar. Geologists say it likely came from the central part of Minnesota and made the trip to where it sits today over thousands of years.

Waldo's Rock Park opened just two years ago in the industrial area of Marion's east side, south of Highway 151 and east of Highway 13. In addition to the rock, the park also features a pond where you can fish, there's a pavilion, windmill, natural prairie, and a paved trail. The trail is literally just a few steps from the Grant Wood Trail. You can see photos of the park below and if you've taken some, feel free to share them below. Waldo's Rock Park's exact address is 6303 Partners Avenue in Marion.

The glacial erratic in Marion is one of many in Iowa, with the largest in the northern part of the state. Pilot Rock is near Cherokee, Iowa. It's about 20-feet high, 40-feet wide, and 61-feet long. St. Peter Rock in Chickasaw County is approximately 80 feet around, and 20-feet tall. A 1964 report from the Iowa Academy of Science took a deep dive into the largest ones in northeast Iowa.

Waldo's Rock Park

The Marion park at 6303 Partners Avenue in Marion is home to what's believed to be Iowa's largest glacial erratic south of Highway 20.

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