Remember to spray goat heads as soon as possible in the spring. A Northmoor Acres homeowner has suggested homeowners use 2-4-D (chemical weed killer) on the goat head weeds, and they need to be sprayed when the little yellow flowers are blooming (if you try to kill them once the weeds have matured, they continue to produce stickers).
Here is the link for Weld County Weed Management