Up sh*t creek...

65LA,
You got a local Home Depot? Go and see if they have a "Tool Rental" area, and see if they have a powered, 100 foot snake! I bet if they do, you can rent that thing for around $50 for the day and let 'er rip! If the little 20 footer didn't work I'd say the 100 footer may.....BE worth it if you get it, without the cost of a plumber! Get good heavy gloves, (They should be able to point those you ought to have for the job), and go through the smallest to the biggest drains in your house, EVEN those floor drains!

Yep this is a difficult one and I BET the clog is right at a pipe junction! You'll feel it when it hits the clog! it will bog down a little...

Hope this helps!