There are so many sections of the main Tygart and it has such a wide drainage area, that there is always water.  When the Tygart is ultra high it has some epic park and play waves, and it's creeks are usually at optimum flow.  When it is ultra low, the Valley Falls section is at its best in late summer.  Despite this, you never have crowds on the Tygart.

Upper Tygart Valley--Class 2-3  (runs at higher flows Spring/Winter) 
The Loop --Class 2-3  (runs at most flows)
The Gorge--Class IV-V (runs at most flows)
Phillipi Section--Class I-II (always)
Arden Section--Class 3-4 (almost always--down to below 500cfs even!)
Valley Falls --Class 4-5  ( below the dam--runs all summer and when the Tygart is at its lowest)

Additionally the Middle Fork runs a lot, and there are numerous creek runs entering the Tygart throughout its length ( Mill Creek; Teter; Laural; Sandy; just to name a few)

I'm pretty sure you can always find a runnable section year round, unless it is iced over in winter.

dbf2