Right now st. vrain drive is closed so you will need to take James canyon drive which will lead you to a gravel road, passable by non 4x4 vehicles. That section will last roughly 15 minutes.
Before you get to Allenspark, you will need to turn onto 3301 also known as Taylor road. It will look something like the picture below. If you are unsure and want to meet before turning onto this road, a good potential meeting spot is at the scenic overlook (40.188792, -105.499101). For those of you that aren't driving a 4x4 vehicle, it is best you stop and park where it says Non 4x4 parking spots (40.193182, -105.484247).
You can see this Non 4x4 parking spot (40.193182, -105.484247) is right in front of someones house but I can assure you, this is a thing.
In these videos, you can see the difference from the start of the road to after the non 4x4 parking spot. There are a couple spots that you definitely want a higher vehicle or a good driver.
If you have a 4x4 vehicle, you can follow the red road till it dead ends. There are pull offs where you can set up camp or park and hike in to the wood some to also pitch a tent or hangout for the day. There seems to be a more extreme 4x4 road that leads half way to Taylor Mountain Trail Head and Big John Mountain. If you stay on the "main road", you will find 2 pull off spots with some trees where you can park and hike down to the creek and camp. This is called North St. Vrain Creek via Bright Trail. If you pass by this parking spot you will come to a split where you can go straight or left. Both will have camping spots and pull offs. It just depends which way you want to be facing.
Parking "lot" for Bright Trail.
Hiking Bright Trail to North St. Vrain Creek
We hiked this trail in July and it got a little wet on us. In a way this is a reverse hike cause you start up high and then descend down into the valley. It is sort of nice because you get to pack in a lot of extra food and drinks and it doesn't suck as bad as if you needed to climb a mountain. Fair warning, it is a bit torturous hiking back out the next day. We also hiked this same trail in November. It obviously gets colder by the river but this means the fire bans are usually lifted so you can have a fire. There is a big firepit already made. Just need to make sure its not too windy and you have a couple dry bags or pop up buckets to fill with water from the river so you can put the fire out.