I think there was no dam. They just gradually filled the cove with dirt, rubble, and trash. And ships, I guess.
I’ve read about all those ships floating abandoned at anchor in the bay. Many of them never even had their cargo unloaded. It seems like that should have been a huge opportunity for salvagers, especially given the hyper-inflated cost of everything in San Francisco at that time. And since so many ships were making one-way trips to San Francisco, you could probably fill a ship with fittings and navigational equipment, sail it back around to the American Northeast, and sell it for a tidy profit. That is, you could do that if you could manage to crew a ship for the return voyage.
