Resources for Teachers

Find A Feature

Welcome to Find-A-Feature Photo Challenge! Each month we will showcase a new geological or ecological feature and challenge you to find something similar in your neighborhood. There is science everywhere - take a look around!

St. Louis Arch

The St. Louis Arch.

(Public domain.)

Our first challenge is Arches! This is a photo of Delicate Arch in Arches National Park. A natural arch forms when erosion removes rock, leaving an opening above. This commonly happens along seashores or other places where there is moving water, because water is great at erosion. It starts with a crack, or a weaker rock layer, then erosion does its long slow work of removing that weaker rock. Big chunks can also break off, speeding the process. Eventually, it reaches a stable shape, and you have a natural arch. Take a look around. Most arches have a similar shape - it happens to be a very stable shape, where the weight of the rock, or bridge, or building, gets transferred to the outside of the structure and is carried by the "legs" so that even a very heavy center won't collapse. 

Find an arch near you! It doesn't have to be a rock, it can be anything with this shape. If you see an example, which can be natural or human-made, take a picture and share it with us by tagging on Instagram @USGS_YES #FindaFeature, or email it to us for use in educational materials at Use the tags #findafeature #USGS #arch #science  Give your first name or initials, general location, and a brief explanation in the photo caption. We will feature some of your shots on this page!





Current Challenge Gallery




We'll be watching Instagram for some great examples, and sharing them here with the first name or initials of the contributor, and a general location only. If you tag us with @usgs_yes you are giving us permission to use your image. If you use #findafeature and #usgs we will see it, but we won't use it. Please see the USGS Social-Use page for our social media sharing policy.