LCA declarations filed for H1B does have salary data. It is there to stop people from exploiting immigrant workers. At least that is the official stance. I am not sure how accurate the numbers are but this site seems to have extracted info from the H1B applications: http://redbus2us.com/h1b-visa-sponsors/ searchable by city. Looking up menlo park tells me, FB was the largest sponsor with median salary of 133k.