Tap into the towns, tools, and characters of our hard rock mining heritage by visiting mining sites of years gone by. Tours are open to ages 10 and older with accompanying adult. Some walking required. 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.