Winter has arrived, and in typical Colorado fashion, there will be many snow, mud and dry cycles before next summer comes back into view. If you're new to Colorado, you may not realize that trails here can't be ridden when they're muddy. Not only does it cause trail damage, but the sticky soils can leave lasting damage to your bike. It's always best to either ride on complete snow cover or to wait until things dry out. But how do you know when trails are good to ride? We've compiled some trail conditions resources to make it easier.
Facebook: the "303 Trail Monitor" page is a constantly-updated source of trail beta for the Front Range. "NoCO Trail Conditions" will cover your questions about trails close to Ft. Collins. For fat bike snow conditions, check "Front Range Fattys"and "NoCO Fattys."
Twitter: @JeffcoOpenSpace for trails in the Golden area, @boco_trails for trails in Boulder County (plus the Boulder Mountainbike Alliance website).
City of Lakewood trails, including Green Mountain and Bear Creek Lake Park are updated here.
Trailforks has a trail conditions listing for each trail (pending user updates). You can see all Denver-area trail conditions aggregated here, but check the date of the last update to see if it is current.
Finally, common sense is always reliable. If you drive to a trail and see muddy bikes/feet leaving the scene, go elsewhere.
Happy winter shredding, and thanks for protecting our trails!