This shot from Chapter 12 of the serial shows the buttressing along the bottom of the photo. I became aware of the buttressing thanks to screen shots from Kurt Spitzer, who runs the wildly informative Spin and Marty site cinchset.com — a site I can enthusiastically recommend to anyone who has an interest in filming locations. This is the definitive screen shot of the buttressing in "Captain Marvel," and also features distinctive background rocks.
Garden of the Gods Park (Bing bird's-eye view)
Here's an overview of the Garden of the Gods area as seen from the east, indicating where the buttressing is located. I recommend clicking on the picture to see a bigger version of it.
Garden of the Gods (1952 aerial photo)
Here's another perspective on where the buttressing is located in relation to the rest of Garden of the Gods, as it appeared in an aerial shot from 1952, during the filming era. The road that was buttressed by the stone structure was part of a network of dirt roads that criss-crossed the movie ranch. It appears to have been a minor road, and is barely visible in the old aerials.
Captain Marvel's Superman-like qualities
Captain Marvel is often compared to Superman, who became more of a household name due in large part to the popular 1950s TV show "Adventures of Superman." This 1941 poster for "Captain Marvel" uses language reminiscent of the familiar "Superman" TV opening: "Faster than a speeding bullet! More powerful than a locomotive! Able to leap tall buildings in a single bound!" Both descriptions appear to have originated in 1941, with the Superman mantra going back to the first of a series of eight revered Fleischer Studios "Superman" cartoons.
"The Life and Legend of Wyatt Earp" (1958)
The stone buttressing in the Garden of the Gods area did not appear frequently in productions, but it does show up in at least one TV show, "The Life and Legend of Wyatt Earp." The sequence seen above and in the shots that follow appears in the episode "My Husband," which first aired June 10, 1958.