I just got back from a busman's holiday on Fall River.  I fished with fellow guides Randy Hamann, Luke Geraty and Mike Wright.  Fishing is good throughout the day with occasional periods of greatness if you're in the right place at the right time!  The predominant hatch was PMD mayflies, both spinners and duns.  The spinners are creamy white and the duns were a pale olive color.  We had good dry fly opportunities from 9-11am, good streamer fishing throughout the day, and pretty good nymph fishing from lunch through the end of the day.  Callibaetis mayflies should start hatching in good numbers soon.  My favorite time on Fall River is August and September - there is plenty of time to book a trip still this season!