This might sound crazy, but a few weeks ago I spent the night in YV right on the banks of the Merced. While watching the river lazily go by, I became mesmerized by the water and my mind followed every curve, rapid and fall of the river up to the various headlands like the beginnings of Fletcher Creek and Lewis Creek. I was really wishing that I was there. I was thinking of the water that was immediately in front of me and how long it took to go from somewhere like Gallison and Bernice lakes or Hanging Basket and Vogelsang lakes. With the Spring flow, I can't help but think the water in the Valley was at these beautiful headlands above 10,000' maybe a few short hours before it passed me buy. Does that sound right?

Many years ago when we went to Yosemite in May to take moonbow shots we were watching the Merced water level rise around midnight. A park ranger told us that it takes 12 hours for high country snow that melts during the day to reach the valley. I have no idea if this is correct or not.

Thanks! looking at the charts, it looks like the ranger might be right. I never knew that. Good reason to pitch a tent over 100' away from a river

It was really interesting standing on the path in Cook's Meadow and you could hear the water lapping up the sides of the river bank as the level got higher.

That's true, and why I turned the hiking group around when we reached a creek that was nearly impassable - four hours later when we were supposed to come back, it would have been totally impassable, stranding us for an unplanned overnight.

while staying in the valley a few junes ago, I noticed that tenaya creek level peaked around 1am (almost flooding our tent-site). it made sense to me at the time that it coincided with the warmest point of the day (early afternoon) -- taking roughly 12hrs to reach the valley. SCIENCE at its best