The first few times I ran Ralston Creek Trail, it was largely on concrete, which is the core bike trail. However, having run some other riparian trails and found that they often have networks of side trails through woods, grass and brush, that's how I ran Ralston on Thursday.
Distance was 6.46 miles, moving time 1:04, elevation gain 146 feet.
The short Leyden Creek trail:
I noticed most people were walking on this bypass between the creek and houses, on the opposite bank from the official trail:
There is singletrack around and through this large field south of Apex recreation center in Arvada:
On the east side looking back: