On a good day, Heather Phinney starts working at 3 a.m. and retires at 9 p.m. Some days are longer. Phinney, 52, runs her own farm, Stillbrook Acres in Gray. She also “freelances” as a milker at Baker Brook Farm, a nearby dairy operation where she milks, feeds and provides basic medical care for dozens of Jersey and Holstein cows, twice daily. But in late summer and early fall, the lifelong farmer spends her days in the city. From the driver’s seat of a horse-drawn wagon, Phinney provides tours of Portland, giving cruise ship passengers a glimpse of historic Portland at the clip-clop pace of Belgian horses. “The work I do is relaxing most of the time,” she said. “It is a good and healthy life.” And for Phinney, it’s part of an ongoing tradition. “My father was a farmer,” she said. “It is the life I know.”