Do you know what a "crater" is? It's like a big hole in the ground, almost like a bowl. Sometimes, things like meteors (big rocks from space) can smash into the ground and make a HUGE crater!
Toms Canyon Impact Crater is one of those big holes in the ground! A long, long time ago, something really big and heavy crashed into the Earth right where Toms Canyon is now. It hit the ground so hard that it made a huge hole! The impact was so strong that it caused rocks and dirt to fly up into the air, and even caused a big shockwave that could be felt far away!
Now people study Toms Canyon to learn more about how big impacts like this can affect our planet. It's like a really cool science experiment, but it happened a loooong time ago!