not in USA, but used to ride lots, road and dirt.
RG400,VT250FG (were quite fast for 4strokes back in 1988!) , various dirt bikes, used to ride the track while owner was tractoring/dozing the dirt to rebuild ramps (just us two was there) id be first testing heights, the lifts, and angle of ramps, he's be watching seeing where i land, etc it was a Lot of fun.
im old now, havent ridden bikes for years, would like to ride again, but i worry ive forgotten how to balance the bloody thing, as i had bouts of tinnitus and vertigo in recent years...sadly but if one day then one day i shall, but if i did, it will be a more relaxed bike....so no more two strokes rockets just a sensible VFR750 or similar
also i worked at Manfeild for World Superbikes Championships rounds 3 times...as a flag marshall, i was more comfortable to race on dirt, road, never had encourageent for the reasons road racing's costs were prohibitive
G