K.K.
Hi! We've done quite a lot of backcountry trips with our almost 4 year old and are starting with our 10 month old. What we've found is that our girls don't sleep as well camping as they do at home, but neither do we! When our oldest was 11 months, we did a couple of High Sierra backpacks (12,000+ feet). The altitude never seemed to bother her, but we did find the elements to be hard above treeline as we were never able to escape the sun or wind. Though we love camping that high, we decided basecamps at treeline work best with dayhikes higher. Kudos to you for taking your little one outdoors-it's a wonderful gift to her (and you!) Feel free to email me with more questions.
Backcountry mama ____@____.com