Interesting ,we had similar circumstances at Lake Gairdner this year ,it was under water for several months but had dried out enough for our meet ,the results were very different though , very hard and smooth ,why ? I believe Bonneville has a high concentration of potassium chloride (potash) where as Gairdner is mostly comprised of sodium chloride and gypsum ,dont know if this has any bearing on how they dry out ,just a thought
Gary