Do the private and semi-private rooms have private bathrooms and showers?

Not exactly, no. Bathrooms are down the hall; several of them for each lodge. That's the best we can do at this site; it's not like a hotel but it seems to work for most people. If you want to have your own bathroom, we recommend off-site lodging, including at the nearby Marconi's conference center, which offers us discounted prices (more info on What's New page).