From NPS.GOV: The 10 Essentials are a collection of first aid and emergency items that can help you in the event of minor injuries, sudden weather changes, or unexpected delays. The 10 Essentials are only the basic items you should have with you. You...
Having proper navigation is important to keeping yourself and others in your party safe. I use AllTrails for maps and trip planning where Garmin inReach devices come in handy or communication and maps when in the back country and other remote areas
Everything you need to keep your skin safe from UV rays!
You never know when you'll find yourself in an emergency where you need a fire to avoid hypothermia, etc
You'll need something to put all these essentials in + anything else you may need!