The park, 60 miles north of San Francisco on the eastern edge of Santa Rosa offers miles of trails for hiking, mountain biking, and trail riding. For wildflower lovers, Annadel Park offers a great variety of flowers from early Spring until early Summer, especially on a hike around Lake Ilsanjo. The best months to see the park's wildflowers are April and May, but there are some plants in bloom as early as January and as late as September.