Help care for your park, have fun, learn new skills and meet other volunteers. And best of all, admission to these programs is free! Declare war on noxious weeds! Join volunteers to rid Castlewood Canyon State Park of those pesky plants. Ranger Sarah Holton will instruct you in the art of weed identification before hitting the trail to remove noxious weeds. This event venue changes based on what weeds are doing well. Be sure to call 303-688-5242 to let us know you are coming and where to meet.