That's because most of the master's degree professions are social whereas science/tech/engineering are bachelor's degree. If you limit comparison to one discipline you see another picture. e.g., for mechanical engineering:
What does a master's degree get you? Well, the median annual wage for all mechanical engineers was $84,190 in 2016. The median represents the halfway point in a salary range from lowest to highest, with the top 10 percent tier earning an impressive $131,350 per year. Specifically, in engineering, more education equals more dollars. Mechanical engineers who have completed a master's program typically will earn 20 percent more throughout their careers than those with only an undergraduate degree.
(Source)
Yes, the statistics are national averages here are the job titles for states with the highest concentrations by education level.
Bachelor's degree
Columbia: public relations specialists, reporters and correspondents, and management analysts.
Massachusetts : Microbiologists, biomedical engineers, and systems software developers
Virginia : ship engineers, nuclear engineers, and information security analysts.
Maryland : budget analysts, atmospheric and space scientists, and middle school special education teachers.
Connecticut : actuaries, aerospace engineers, and marketing managers.
Master's degree
Columbia: Political scientists, economists, and historians
Massachusetts : industrial-organizational psychologists, statisticians, and healthcare social workers.
Vermont : urban and regional planners, nurse midwives, and mental health counselors.
Maryland : statisticians, mathematicians, and epidemiologists.
Delaware
Most of the Bachelor jobs above look like private or private/public sector roles whereas the Masters jobs appear purely more towards government and academic end of the spectrum where lower incomes are the norm.