Forbes surveyed 70,000 American workers at companies with at least 500 employees.
"Surveys were conducted anonymously, allowing participants to freely share their opinions," the publication writes.
Participants were asked to rank their employer in a series of categories, including:
- Safety of work environment
- Competitiveness of compensation
- Opportunities for advancement
- Openness to telecommuting
The results were divided into 51 rankings, one for each state plus the District of Columbia.
Here are the top-ranked employers in Iowa, according to the survey: