Try not to launch from Boulder County Open Space as there is a hefty fine involved if and when caught. High School athletic fields are generally large enough to accomodate up to C powered rockets, if you take the wind drift into consideration. If you launch from the Superior Community Park, apart from the soccer games going on, you should be alright. Jeffco or whatever it’s called now is close (within five miles) but as long as you are flying rockets up to or less than 16 ounces in weight, typically powered by 1/4A to E motors, there is no reason to interact with the federal government – just fly’em by the Safetry Code and enjoy. Once the threshold of 1 pound (rocket weight) or 125 grams of propellant is crossed, the FAA gets involved and at that point you should be flying with a NAR or TRA sanctioned club. Hope this info helps.