between Moab and Castle Valley sometime today. This part of the Wingate escarpment along the Colorado River had been previously shedding rocks a few months before (on 18 August), but this large rockfall placed enormous sandstone blocks in the river. New obstacles for next year’s river runners.
In speaking with some residents in Castle Valley, the consensus is that this occurred sometime mid-day today, and is not correlated with the small local tremor of the 20th.