Since this cache is located next to a busy highway, please be very careful on your route to it. I suggest you park behind the City of Marshfield - Street Division - Sign Shop, east of Oak Avenue. There is parking, year-round, in the G.P. Olson - West Field for the soft ball fields. Both are behind the "Old Armory Building" - now called the Oak Avenue Community Center.
Cross Oak Avenue and walk the bike/hiking trail north to the top of the hill. Now, I suggest you cross the tracks and traverse the city's mowed grass west.