We found abundant agate on the slopes of Agate Hill, just southeast of Panguitch, including fairly large pieces in assorted bright colors. It is a fun spot to take kids were they will certainly find plenty of interesting shiny rocks.
Colors include a lot of pear and reds, but also many other many other shades and some black. I don’t remember any other spot where these is so much black agate.
The access road is good graded dirt, so it is fine for any vehicle during dry weather but can be dicey when wet and impassable for most vehicles during the dead of winter.
There are many good undeveloped campsites in the area, including some where you can find plenty of agate in and adjacent to your camp. There is a fun site with a great view on top the hill but you need a high clearance vehicle to get on top.
We parked along the main road on the east side of the hill and searched adjacent slopes with plenty of success. We also drove around to the NW side, where there is a nice campsite along the main road, and found excellent rocks everywhere.
The access road leads to the Casto Canyon Trailhead, which is just east of Agate Hill. The area is very scenic with Bryce-like formations. It is forested. The elevation is relatively high and so summer temps are generally mild. Winter days are cold and winter nights can be extremely cold. The area does get significant winter snowpack.
It is a great, can’t miss, fun spot for family rockhounding.