This month's How Curious explores how the work of two African American property developers and entrepreneurs proved ground-breaking both within Oklahoma City and beyond on both a literal and metaphorical level.

A few months after How Curious host/producer Rachel Hopkin moved to Oklahoma, she was given a barite rose rock by two of her dear neighbors. It came in a box with a short text attached which stated that to hold it was “literally like holding a quarter billion years of history in the palm of your hand.” That gift provided the impetus for this episode, in which Rachel finds out more about this geological bloom and why it's unique to just one part of the Sooner state.

It's almost impossible to imagine life without the shopping cart today. However, it was invented less than a hundred years ago. Rachel Hopkin explores how it came about, its pervasive impact, and the role that the Oklahoma inventor/entrepreneur/philanthropist Sylvan Goldman played in its success.

How Curious host/producer Rachel Hopkin the world's largest institution that’s solely dedicated to revealing and exploring the form and function of the skeletal system and which is based right here in OKC.

Seventy years ago, a landmark psychological study that has been described as a real life Lord of the Flies took place in an Oklahoma state park. But although the Robbers Cave Experiment, like the novel, focused on a bunch of schoolboys, it offered a very different perspective on human nature.

Which Oklahoman Got a Hippopotamus for Christmas? Today’s story features a local girl with a belter of a voice, several hippopotamuses, some zoo history, and a hit song.

Kendall’s Restaurant in downtown Noble, Okla., is famous for chicken-fried steaks, cinnamon rolls, and GHOSTS. Rachel Hopkin explores some strange goings-on under its roof.

The Morgan Horse is the earliest surviving breed of American horse. But it's from Vermont. So why is it so important to Oklahoma?

Which of Oklahoma's cities was designated "America's Model City" in 1951? And how did the diminutive Shetland pony help that city to grow?

Many settlers in Oklahoma are of German descent but had ancestors who lived as Germans in Russia for a century or more. Who are these “other Germans?”