If you visit the hike description page for the Dutchman Trail: http://hikearizona.com/decoder=569
and then click on the map on the right side and choose "official route", the following page opens for you:
It's a GPS track of the entire dutchman trail. On the left side is a diagram that shows the elevation profile of the entire route. You can move your mouse along it and it will show your progress along the route. Including the distance.
From what I see, the trail junction of Dutchman and Bluff Spring is at 5.6 miles.
You can change the layer of the map view to one of the Topo maps from the pull-down menu in the top right. That way you can see the names of topographical features like Bluff Spring Mountain, whereas the Google Map layer doesn't identify geographical features.
But, as Joe points out above, if you are trying to get to Bluff Springs Mountain, there are more direct routes than the Dutchman Trail.
I hope that helps!