I use Courtney Molini from Hands on Horses. She is very reasonable and does a great job on our show horses. She is based out of Ellicott City, but comes to our barn in Mont Co. her number is 410-379-0869
Can't say enough good things about her. I have been using her for 7(!!) years (And she came highly recommended). She is fantastic. And reasonably priced. She is from WV, but does horses in MoCo, Frederick, etc. She gets around.