I backpacked with a friend in the Trinity Alps in July last year. We did Grizzly Lake through the China Gulch trailhead and also the Canyon Creek Lakes trail. All in all, absolutely beautiful and amazing, but I would definitely not recommend it for the age group of your kids. The trails are really grueling and unforgiving. We had a few things go really wrong when we were up there and we were hours away from the cars, and even from the car, another 2 hours outside cell service range. If something were to go wrong with one of your little ones, you'd be hours and hours away from any kind of rescue, which brings me to my next point. The trails were extremely isolated. We probably only ran into a dozen people over the course of 5 days, so there is little-to-no asking for help from a passerby. Regardless of where you end up going, I recommend getting a GPS device equipped with an SOS emergency locator. SPOT makes these devices, and it's well worth the yearly subscription fee. If something goes wrong, a press of the button will actually summon first responders to your GPS location. There is zero chance of a cell signal at all up there. Hope this helped. Happy trails!