One thing to note about Colorado weather, is it can be unpredictable, particularly in the mountains. It’s why if you want to hike a 14er, you need to start early in the morning so you can be off the mountain in case a (brief, yet somewhat common) afternoon thunderstorm rolls through.
Rifle Gap State Park is only at about 6,000 feet, but is still susceptible to rolling weather. The upside, besides some much needed rain, is often the light is pretty spectacular.