The roads I was talking about?
The easiest way is to take I-80 to Cherry Glen Road Exit. It's halfway between Vacaville and Fairfield. That road basically turns into pleasant valley road which connects with 128 around Berryessa. If you go past the lake on 128, to the first fork in the road, and follow that right, you will come to Knoxville Road (lower lake road). If you're confused, tell me I'll explain a little better.