Forest is an unincorporated community in Lewis County, in the U.S. state of Washington. It is located on Jackson Highway, between the Port of Chehalis and Washington State Route 508. Two reliable but differing accounts of the name of Forest exist. One theory is based on old-growth timber that grew in the area, while a second option posits that the mo…Forest is an unincorporated community in Lewis County, in the U.S. state of Washington. It is located on Jackson Highway, between the Port of Chehalis and Washington State Route 508. Two reliable but differing accounts of the name of Forest exist. One theory is based on old-growth timber that grew in the area, while a second option posits that the moniker was taken after John T. Forrest, an early school teacher in the community.