22 May Kelso Dunes, San Bernardino Co., CA. we stopped where grass began to grow the humming also stopped. So Dave went up another nearby dune slope and slid down alone; this time the sand really began to hum and the sliding sand continued humming for about 20 seconds. The rest of us did this dune and we had the same effect- the sand hummed for about 10 seconds after we stopped sliding. when we finished sliding I was thoroughly covered with left over sand, both inside and outside my clothes- even in my ears. we arrived back at Dorners Camp we (Claudia, Dave, & I) went for a swim in our wonderful (but small) cement pond. At night the UCB people set up mist nets to catch some bats. At about 2100 PST we had caught three pipistrelles and five Big Brown Bats, all of which we examined and released (Species accounts: Western Pipistrelle; Big Brown Bat). Now I'm tired so good night.