Easy Hike. Spring forward and join us for a leisurely walk at Carolyn Holmberg Preserve where we will look for signs of spring’s return. Join volunteer naturalists in exploring what makes spring the great awakening that it is. Registration required. Register Registration is required through Discover Boulder County, Parks & Open Space’s volunteer and event registration system. If you’re new to the system, you'll need to create an account. But it’s easy and we only use your contact information to communicate about events you register for. We will never sell or give your information to a third party.