More than 100 were on hand to lobby state government on issues including the welfare of indigenous women and children, and a planned liquified natural gas facility in Tacoma.
The bill has support from Attorney General Bob Ferguson.
The march, which is timed to the anniversary of Roe v Wade, took place as legislators considered bills that would broaden access to abortion services.
The hearing attracted passionate testimony from both sides of the issue.
One Senate bill would prohibit internet service providers from exercising “deceptive” tactics and impairing or blocking legal web content.
In his State-of-the-State address, the governor made the case for an ambitious carbon tax.
