merkin4 from St. Peters MO on 5/17/2011 1:13:22 PM:
Highway 94 is undergoing construction between 64/40 and Defiance MO. For the next two weeks (mid and late May 2011) the road is closed, cutting off all drive-in access to the Weldon Spring trailhead.
Alternatives in the area include access from the Business Park trail to the northeast, or Defiance to the southwest. The Business Park trailhead starts near a sewage treatment plant, and the mosquitos seem to be fierce and impervious to any repellant short of a flamethrower.