I certainly defer to the experts on this list about the OS Flycatcher ID being highly doubtful.  More than one person has mentioned that it would be rare.
However, it was a very loud and clear "QUICK three beers!!" repeated more than once (after a short pause) in the same area.  It was heard in the pine woods between the parking lot and the path that splits to the two falls, on a dark cool cloudy morning around 9:00am.
I didn't hear any indication that it was a mockingbird or catbird (since it was the only song it was singing).  I guess it could have been a starling though, having a little fun with a novice birder! ;-)  But I didn't hear any other starling-like sounds in the area.
Jenny

-------------- Original message --------------

> Jenny
>
> Olive-sided Flycatcher in Garrett this time of year would be remarkable.
> The earliest report of returning migrants from way up north (e.g. maybe
> northern Michigan) is August 2. You may have had a Starling, Mockingbird,
> or some other mimic but not likely a real quick-three-beers. Bob Ringler
> may have earlier dates but the current yellowbook is my source.
>
> Regards.
>
> George
>
> ----- Original Message -----
> From: "Jenny Mcclintock"
> To:
> Sent: Monday, July 12, 2004 12:19 PM
> Subject: [MDOSPREY] Garrett County Weekend Trip!
>
>
> > Thanks to all those MDOsprey experts who provided birding tips for Garrett
> County, my husband and I had a great weekend! The weather was great and I
> added quite a few birds to my growing life list!
> > We arrived at Carmel Cove Inn in the central area of the Deep Creek Lake
> on Thursday evening, and had a nice deck with a great wooded view, so I
> didn't have far to go to see some great birds! From our deck I saw:
> > · Great-crested Flycatchers (I have heard them before, but never
> seen one. We had a great look at a pair who spent the weekend with us)
> > · Red-eyed Vireos (they were not shy at all and I got a good
> close-up view of their red-eyes)
> > · Eastern Phoebe (flying back and forth to nest under the eaves of
> the Inn)
> > · Common Yellowthroat (singing constantly, but not visible)
> > · R.T. Hummingbird (a pair flew up for a quick visit)
> > · Song Sparrow (heard several)
> > · Chipping Sparrow (taking a dust bath)
> > · Veery (heard, lifer!)
> > · Black-billed Cuckoo (heard)
> > · Wood Thrush
> > · Lots of Blue jays, Catbirds, and Crows
> > On Friday morning, we visited Herrington Manor SP and I had the highlight
> of my weekend. An adorable male CHESTNUT-SIDED WARBLER sat in plain view
> the sunlight and sang and preened for a good 15 minutes! Apparently he was
> very "pleased, pleased, pleased to meet us"! He was SO cute! Also got a
> quick look at a beautiful bright male BLACKBURNIAN WARBLER sitting high atop
> and pine tree. Both lifers for me!! Also saw/heard most of the same birds
> listed above.
> > Saturday, we visited Swallow Falls SP. What a beautiful place! I heard
> many BLACK-THROATED GREEN WARBLERS (but couldn't spot any - it was a bit
> cloudy and very dark in the woods). But I got a good look at a MAGNOLIA
> WARBLER (another lifer!!). Also heard,
> > · Olive-side Flycatcher (lifer! quick, three beers!)
> > · Cerulean Warbler (lifer! I'm pretty sure I heard 2 of them)
> > · Acadian Flycatcher
> > · Great-crested Flycatcher
> > · Solitary Vireo
> > · Yellow-throated Vireo
> > · Red-eyed Vireo
> > · Pileated Woodpecker
> > By the way, I had a MYSTERY BIRD singing all weekend outside the Inn. He
> sang the same song most of the day, but I couldn't see him and couldn't for
> the life of me figure out who it was. He appeared to be high in a tree at
> the edge of the woods next to a small field (along with the Yellow-throat he
> was the most consistent vocalist of the weekend). His song was a clear and
> musical:
> > - ___ ___ ── ── ___ ___ - - -
> > deet dah-dah dee-dee dah-dah deet-deet-deet
> >
> > .with the last three notes a quicker three-note trill. It is probably a
> very obvious bird, but I am stumped (which isn't very hard!). If anyone has
> a clue who this might have been, please let me know.
> > Thanks again for all the help!!
> > Jenny McClintock
> > Columbia, MD