In a detailed look at how women are faring state by state, researchers considered four factors: Women’s median pay for full-time work, the proportion of women working in jobs considered managerial or professional, the level of women’s workforce participation in each place, and the gap between their earnings and that of their male counterparts.

Here are the top five, along with the median pay for women with full-time jobs:

1. District of Columbia $60,000

2. Maryland 49,800

3. Massachusetts 48,500

4. New Jersey 48,000

5. Connecticut 46,000

And here are the bottom five:

47. Arkansas $30,000

48. Mississippi 30,000

49. Louisiana 32,000

50. Idaho 30,000

51. West Virginia 30,300

The far higher cost of living in the top five is reflected in the higher salary figures, notes study director Ariane Hegewisch, as is “the abundance of the best states’ managerial and professional opportunities for women in fields like law, finance, and insurance.”

Women’s much-discussed wage gap shows up clearly in the IWPR data. In Washington, D.C., for instance, that $60,000 median salary is 87% of what men earn in comparable jobs. The gap is wider in many other states where women make less, like Minnesota, whose median women’s salary of $40,000 is just 80% of what men earn. In Delaware, women’s median salary of $41,000 is about 82% of men’s.

“Higher pay does not mean more equal pay,” Hegewisch points out. “That’s partly because, in the most lucrative private-sector industries like Wall Street, women don’t get promoted to the highest-paying positions as often as men do.”

Extrapolating from data the IWPR has gathered for the past 40 years, Hegewisch and her team calculate that “even in the best states, our projections don’t show women’s pay reaching full parity with men’s until 2058,” she adds. “In the worst states, it will more likely be sometime in the next century.”