Tom, the site you are referring to is the Cretaceous site behind the Maryland Science & Technology center at the end of Beliar Drive in Bowie.  I live just down the street from it and unfortunately it is no longer a viable spot for collecting.  The collecting area was located in the bank of the stream down behind the facility.  You had to let the guards know that you would be walking near their secured perimeter/fence in case you bumped it with your shovel or something becasue it has motions sensors.  In any event, the area of the stream in which the fossiliferous layer was "exposed" has been severely gutted and all of the material removed.  Folks tried to start other smaller holes left and right of this spot however, the landowner above, whose house sits right next to the edge of the tall wall, has posted no tresspassing signs everywhere.  To be honest, I don't know if they own the rights to the hill, or if the facility does, but I do know that the last time I parked my car by the guard shack and walked down into the woods just to see what things looked like, when I returned there was a police officer standing there waiting for me to question me as to what I was doing.  After 911, facilities like this don't take too kindly to folks just leaving an unattended parked car near their facility.  With all of the material to be collected gone, your only hope is to walk up and down the stream and look for something that may have washed out years ago, but if you do find something, it's always broken and beat up.  The MGS (the club I belong to) still tries to go down there occasionally to walk the stream and sift for some of these leftovers I mentioned earlier. 

Daryl.

   Tom - since you were asking about the Bowie site, I thought I might suggest another.  I've heard there is a good site on an exposed hillside somewhere near the intersection of Wheeler Road and Wheeler Hills Road in ?Oxon Hill?, Maryland.  I have not been there myself but I have head good things about it and it may be worth checking out since it is also of Late Cretaceous Age in the Severn Formation. 

I've been to the Oxon Hill site a number of times, but have only a small tooth fragment & bone sliver to show for it.  It's primarily known for the presence of nodules of the mineral Vivianite (a denim blue iron phosphate).  I had heard that in times past fossils could be had there, but in my 10+ times of going, I've never found a thing.  The real estate sign that is there suggests that someone might try & develop it at some point, which might be productive.

Keith