Tent options for 3

I don't know how you're going to get privacy with 3 in a lightweight tent, especially since the average 3 person tent is more suitable for 2. But I really like the REI T3 I got on sale, surprisingly light. Don't know if I'd want 3 people in it, but I might if two were girlfriends. You should probably look into a superlight 1-person, and a 2 person.

I got the Rainshadow 2 from tarptent this summer, it's light, a smart design, and customer service is legendary. It's probably you best option for using alone and we had minimal condensation down into the 30's. It will also teach you skills like seam sealing and pitching a non-freestanding tent with it's vent to the wind. As for privacy, they should probably let that go and be happy with a gentlemanly turned back. Unless you're a gentleman enough to carry an extra 3#'s or shell out an extra $200 on an msr mutha hubba. Oh and I'll vouch for rei tents, not the lightest but great tents.

Check out the Big Agnes Copper Spur UL3. Used it with my family in RMNP. My scale weighs it at 70 oz (4lbs 6 oz)with ti stakes, poles, fly and stuff sacks. 44 sq. ft. of space which is really nice. Set it up in Fast Fly mode for going solo and save about a 1lb. It is a little spendy though. I found it on sale.

I agree with Joe that most 3-man tents really accomodate 2, but if one is a child a Black Diamond Skylight would work in the conditions you describe, though some gear would need to be stored outside. Take a look also at Stephenson's Warmlite 3R (www.warmlite.com), which is probably the most space for the weight, though very expensive – $700+ with side windows.

If your family can deal with this, both a BD megalite or a Go lite version are quite light per person and the BD has a bug net/floor option.

Thanks for the ideas…

Does the tarptent hold up in winds? Cold? It looks most 'flinmsy'

What about the Mandatory Gear Puppy Pile? I don't know much about them, and they are pricey, but I've never seen mention of it.

This tent is a non-starter for 3 people. See Ryan Jordan's review: http://www.backpackinglight.com/cgi-bin/backpackinglight/mandatory_gear_puppy_pile_tent_review.html

There is a wide variety of options out there. My first choice would be a pyramid or tipi shaped tarp. Tarp, stakes, ground cloth less than 3lbs, down near 1lb if you go with one of the really high tech materials. This isn’t the best option if you want good bug protection with ventilation.

A bit less storm worthy than a pyramid tarp(but plenty good enough for any 3 season trip in the sierras) with better bug protection would be the tarptent rainshadow2 which is only 2.5lbs assuming you are using hiking poles.

If you really want double walled shelter then I would suggest looking at the BA Copper Spur if you are looking for a freestanding shelter, or one of the 3 man tunnel tents (Warmlite etc). As others have noted, most 3-person backpacking tents have room for three people who are stacked next to each other without room to move.
If you really want

For more thoughts my shelter recommendations

I bought the REI T3 this year. It is short in length, but otherwise it is probably big enough, though tight, for a couple and a child to fit in. At 4lbs or so, it is also about the lightest 3 person tent out there. The BA copper spur looks nice, but that is just way out of my price range. I find the T3 to be very breezy, so can be cold inside (but the upside would be well ventilated on a hot night). The vestibules are very small, but 2 doors are nice. I find the pole configuration to confusing and hard to set up, and I have set up lots of tents over the years (this is a tent that many people would not be able to figure out without instructions or me to help if they were on their own).

Kids love to jump in and out of tents and do the zips, etc, so I am not sure how well the lighter tarp tents would do for that use. I would love to get a tipi style tent though too, and you should definitely consider that if you won't always need bug protection and/or want something for 4 seasons.

I used the above in the Sierra most of this summer with my girlfriend and it was great space-wise; with three it would be snug but manageable I guess.

I am not really familiar with the areas you mention terrain and weather-wise but we pitched on hard surfaces pretty much and did not get the opportunity to use it in the rain.

The main drawback it had IMO is the entry height which is low, but liveable with.

It's cheap! Well it is compared to the UK price; I bought mine in the US.

I have had good results with three in this tent. It is a lot roomier than most "two person" tents I have tried. Construction is excellent, as is headroom for such a light tent. The two vestibules are nice for your gear also!

I own a lunar duo and I LOVE this tent.
However, I would not recommend it for 3 people. Someone would likely get pushed up against the tent wall and get wet from condensation. I haven't ALWAYS had condensation inside but usually do and while not an issue for two people because of the roominess, I think that is would become an issue with three.
YMMV

MLD's silnylon Mid weighs in at 21 oz and is "… a palace for two or three…". It would be to big, IMHO, for solo use but there are many great options for that. At a cost of $275.00 it is affordable and is a well made and proven design.

This is a shelter and not a tent.

3 big boys with scratchin room per?

These two customize too and post here:

mountainlaureldesigns.com Spinntex EXP MID
Bigger than Golite Shangri-La 3 & Black Diamond Megamid range:
mountainlaureldesigns.com 2009 Silnylon MID

Even bigger and taller:
Owareusa.com: click on ‘Pyramid Tarps’

These two are more pricey but stand up to very high gusts in open areas better which is probably overkill for you + accommodate collapsible stoves:
Titanium Goat.com Vertex8

Kifaru 4 man Tipi