First I want to start with the TH. The directions given are funky and confusing on the link of this site. I would follow this link for overall better information: https://hikemtshasta.com/trails-further-afield/trinity-alps-trails/grizzly-creek-trail/ I found that many people slept at the trailhead the night before. We slept at the North Fork Campground right at the turnoff to the TH. It is a pack in/out campground with a bathroom. We were the only ones there while the TH was crowded with cars. There seemed to be plenty of parking at the TH. Mileage on this site is very off! I had 2 GPS devices and both read just over 8 miles one way to the meadows and another 1 mile scramble to the top of Grizzly falls. This means that round trip it was just over 18 miles. Be prepared for that. This was a beautifully amazing hike that was extremely difficult. If you are in shape you will have no problem. There is plenty of water along the trail so you don’t have to pack it all. Camping is in the meadow and there is space across the water. The scramble was insane and going down was even a greater challenge. People were camping at the lake, but it is more exposed in thunderstorms, which there were when I was there. It was also 91 degrees which made this hike even a greater challenge. Wildlife and deer are plenty. DO not leave ANYTHING outside your tent except for the food you hang. The deer will eat it. They did that to my friend and several other hikers.
I highly recommend this hike for fit people who want an extra challenge. The views are stunning and worth it.