Is there a way to find GPS coordinates on an offline iPhone that is lost in a field?

I wasn't sure if you can find the last location of a cellphone using GPS coordinates even though it is offline. I know it is not stolen and it's been 3 days since I lost it. I haven't found it yet. I lost it in a corn stalk field and had not backed it up for awhile, so I lost all those pictures. I tried the Find My Phone App but it was too late before I could get signed in to my Apple account. It kept asking me to verify my account with my phone number but I did not have my phone to verify it. My location settings was set to on.

Or does anyone have any ideas of how to locate a missing cell phone in a stalk field? I have been walking the field with not much hope.

Thanks.