Category On Menu Bar

I realize this probably a simple fix and I may not be thinking through this completely. But…I use a category in the menu bar and put PAGES underneath it as sub categories in the menu. It works fine unless a user clicks on the CATEGORY in the menu bar. If that happens, they get taken to a PAGE NOT FOUND.

Any ideas on how to fix this or is there a better way to set up my menu?

Thanks!

Here’s the site: https://www.rpidaho.com