To make the rosemary syrup, combine equal parts water and sugar in a pot. Add several sprigs of fresh rosemary. Heat mixture until just barely simmering and remove from heat. Let the syrup steep for 10 minutes, and then remove the rosemary.
In a rocks glass combine the whiskey, rosemary syrup, and orange bitters. Add ice and stil to chill the drink. Garnish with a rosemary sprig and an orange peel.