My husband and I will be visiting the Grand Canyon with our daughter (17) during the summer of 2010. Rooms on the South Rim are already booking. What about the hotels in Tusayan? What are the downsides to staying slightly outside of the park?

You can't walk to the Grand Canyon rim from Tusayan (it's 11 miles, so it's not simple stroll).

Also, since you're outside the Park, you'll have to stop at the entrance booth each time you go to there. If there's a line of people hoping to get in and see a sunrise, you'll have to wait for them.

We have visited quite a few National Parks and stayed both inside and outside Parks - the Grand Canyon is the one I most recommend staying in Park lodging. Unlike some other Parks, it is quite a drive from real world lodging to the Canyon, with little else between. (Unlike, for example, Yellowstone, where slightly outside really means a fraction of a mile from something to see)

In my experience hotels at the Grand Canyon get completely booked far in advance. There is no penalty to cancel up until 2-3 days before arrival, and tour group operators can book blocks of rooms.

When I visited late June 2008 I found that about 1mo ahead of time cancellations started to become more frequent, but also quickly were rebooked by people checking every day.

On the day of our arrival I could have simply walked up and gotten a room at any of the hotels except El Tovar, apparently due to many last min cancellations.

My recommendation is to make a cancelable reservation at Tusayan, then about 3-4 mo before your trip check back at the xanterra.com website (or call them) from time to time. As your trip approaches as does the cancel-by date for your Tusayan hotel you can check more frequently.

There are several advantages to the Tusayan hotels, including AC and a pool at some hotels. I agree with gail though - stay in the park if you can, simply for the ability to walk to the rim from your hotel any time of day, especially before and after the day trippers crowd the place.