Sunnyvale is a rural, sparsely populated affluent town in Dallas County, Texas, United States. It’s the east most city of the county and it has more than 5.000 residents. The town changed hands from Mexico to Texas a few time throughout its history. It started to develop after the Texas revolution. Sunnyvale is along Lake Ray Hubbard, which has recreational activities for Sunnyvale residents. It has four nature parks protected by the local regulations. The median income of a family living in Sunnyvale is just below $100.000 per year.