My opinion on this topic depends on the location of the proposed bike 
trail.  I note that the trail already exists, in fact if not formally 
designated, between the Sherwood Farm entrance bridge and the Willow 
Grove Farm entrance bridge, on the northern (river left) side of 
Minebank Run.  New construction would involve a connection between Loch 
Raven High School and the Sherwood Farm entrance bridge, and another 
part from the Willow Grove entrance bridge along what is presently a 
dirt road to Loch Raven reservoir property.  This downstream section is 
fine habitat, but I note that bulldozers rearranged the streambed of 
Minebank Run a few years ago without significant long term effect on the 
birds we love to see here.  If bike trail construction takes place in 
the winter, disruption would be minimal.

If the proposal is to put a new paved trail on the south side (river 
right) of Minebank Run, I would oppose that as ecologically unwise, 
given the better alternatives listed above.

Full disclosure: I am the author of "Baltimore Trails: A Guide for 
Hikers and Mountain Bikers".  So my perspective is not exclusively that 
of a birder.

Bryan MacKay
Catonsville MD