Yard hydrants

Hello all. I'm the new guy. I have recently moved rural and am on rural water. I have a well with an opperable 220v submersible. I have three hydrants in the yard, all are dry, even on the rural water. The well is too shallow for the house, but would be great for cattle and garden. My problem is I can't figure out where the end of the main line supplying the hydrants is. I really don't want to dig up the yard to find it. I just want to find the end and trench it to my well. Any ideas? The original owners are long gone and I have no blueprints.

Metal detector?

Or a couple pieces of wire bent into EL's.

You may be able to witch for the lines.

The Schoenstadt locator I have mentioned before will actually find the joints in pipe if it is metal (steel) pipe. Of coarse if you have to buy one instead of borrowing one, you would be better off to rent a backhoe and go to digging.