Super pretty trail all the way down to the river. It's shaded with lots of greenery. There are some pretty difficult parts of this trail. Rock scrambling and some very narrow parts with steep drops. I suggest you be in pretty good shape for the climb back up. Bring a backpack with water, food, and salt tabs.
The drive there was pretty confusing. We clicked on the directions button and followed that. Windy narrow road that turns to rough dirt road after crossing the river. Continue up for about 7 miles. If you are following GPS, it will show you have arrived before you actually have arrived at the trailhead. Keep driving and you will see the humbug trail sign and a small turnout to park. On the way out, we drove the other direction through North Broomfield. Follow the paved road and it takes you back to 49. It's a longer drive, but better than the dirt.