Located at 2995 Hansen Road in Livermore, California and named after the Holdener family who operated a drive-in dairy. The dairy closed in 1980 and in the 1990's the Zumbach family developed a portion of the 102.5-acre ranch and gave 55 acres to the Livermore Area Recreation and Park District as a mitigation requirement. In 2008, Livermore Area Recreation and Park District opened the park as an open space park which features a multi-use trail perfect for hiking, biking, and horseback riding. Explore the open grasslands where spring wildflowers make a showy appearance, and small ravines with majestic blue oaks that provide shade. A variety of insects, mammals, birds and reptiles can be seen here. Look for deer, red tail hawks, great horned owls, a variety of butterflies and western fence lizards. Vehicles are encouraged to park at the end of Hansen Road near the water tanks; there is no running water or restrooms available. Pets are welcome but must be leashed at all times while in the park and on the trails. The park is open daily, Sunday through Saturday from 7:00 a.m. to sunset.