Orion Redwood grows far up Elam Creek, a major Redwood Creek feeder stream. I have not hiked to Orion, so showing an overhead view of the tree and area from Google Earth.
The average diameter at 4.5 feet above ground level is 13.7 feet.
As part of plot research Orion was measured at 369.4 feet in late 2015 or early 2016.
This is a slight decrease from the 2015 published height of 370 feet. This could be from a difference in the determination of average ground level (since the tree grows on a steep slope) or maybe the crown lost a little height.