Thanks for the replies so far and the sites that have been provided.
Bobj3, yes it is a bit of a root ball. The main thread for this project is under
Jigs and Fixtures - Large router sled.
Del, not butternut as we dont have that here, elm in very very limited quantities. There was no smell either when I routed the top or did any sanding.
Upstream of where I retrieved this piece the river runs through millions of acres of softwood such as fir, pine,cedar, spruce. Mixed amongst this are aspens, cottonwood, and there are some lowland valley farms which could have anything planted on their banks.
Dovetail has kindly offered to examine a piece of this driftwood and provide a scientific identification. So thanks all for now and we will await Dovetails results which will be posted on the original thread for the project.