How do I know where the main sewer of my house from the tress

Hi AMH and welcome to The Plumbing Page on AMHD.
You piggybacked on a 2 year old dead thread so I gave you one of your own. Before you post look in the upper left hand corner for the date..
Are you on aseptic tank or city sewer? Why did you mention trees? Have you had backups and clogs? Back to you, Tom

There are 3 basic ways to look for main sewer pipe:

1. Look for Clean Out. Some cities have Codes that require sewer clean out within 24" of the house foundation.
2. Go in front of your house and look on the roof. See if the vents line up. If so, sewer (may) go in direction of vents
3. Call plumber with pipe locator

Back to you. Milo