I did some homework and found some information to share. (Sorry it's a bit long.)
Before we can go, we have to make reservations with the tribe. It costs $30 per person to enter the reservation to hike, plus $12 per night per person. (Plus a $2/group `environmental fee'.)
The Havasupai tribe is at the west end of the Grand Canyon, nearer to Kingman. It will take 7-8 hours by car to reach the parking lot.
From the parking lot, it is an 8 mile hike to the Havasupai village, which has services (cash only). Yep, you can't get to the village by car.
From the village it is another 2 miles to the campground. The lovely waterfalls are near there. The campground has ameneties such as running water, composting toilets, etc. No campfires allowed.
The tribe calls the trail `moderately difficult' and discourages hiking at night. They ask visitors not to unless they are familiar with the trails. My coworker who has been on the trip said the trail has several long stretches of switchbacks that are treacherous and difficult and said he would not try it at night, even under a full moon.
If we go, here is our itinerary: Leave on Thursday, June 8th, after work (6ish). That would get us to the parking lot at 2 or 3am on Friday morning. We would hike the 8 miles to the village and arrive there late morning. Upon arrival at the village, we check in with the camping office and get our permits before proceeding to the campground 2 more miles away. We'd stay overnight Friday night, and possibly Saturday as well. If we left Saturday, we'd get back to Tucson very late Saturday night or early Sunday morning. If we left Sunday, we'd have to hike during the day on Sunday and get back to Tucson late Sunday night.
I have some concerns about this trip... mostly about the degree of exhaustion we are likely to deal with: on Thursday we'd work all day, then get in the car to drive 8 hours, then backpack 8 miles. Then we turn around and leave within 36-48 hours to do it all over again (backwards). If we decide to hike during the day instead, June is going to be brutal hot. Backpacking in 90+ degrees for 10 miles each way doesn't sound fun to me.
So... I suggest planning a Havasupai trip in March or April of next year, hiking in during the day. Or going at night over a longer stretch of time to reduce the exhaustion factor.
Since there seems to be lots of interest in a nighttime backpacking trip in June, perhaps we can choose a destination that is more accessible to us? Any thoughts?
More info on the Havasupai area: http://www.havasupaitribe.com/index.htm