 Most of the trail-work has been completed by volunteers and the Washington Conservation Corps, sponsored by the city of Newcastle.The trail system will eventually lead all the way to Lake Washington to the west, in conjunction with Renton, and is already connected to Cougar Mountain Regional Wildland Park to the east, which is in unincorporated King County.The city has not obtained its own ZIP code even though, based on the ZIP code designation, some sales taxes paid by Newcastle residents go to Renton instead of Newcastle as tax revenues (among other perceived detrimental impacts related to mail service, insurance rates, property values, and credit ratings).