There is interesting rock art carved into black lava rocks west of Fillmore, in west central Utah. The area is known as the Devils Kitchen and is found along the Pahvant Valley Heritage Trail. People enjoy exploring the area using all terrain vehicles.
(This is not the Devils Kitchen scenic area in the tops of the mountains along Nebo Loop. This is low desert country.)
If you are in the area, it is worth searching out the rock art here. But the rock themselves are not particularly unique or impressive and, in my opinion, it is not worth a special trip just to see them. There are plenty of more impressive sites in the region.
The tiny farming community of Flowell UT, west of Fillmore, is the jumping off point for visiting Devils Kitchen. From there, the good gravel Clear Lake Road skirts lava fields as it runs NW up to the Clear Lake Waterfowl Managment Area.
The Devils Kitchen turnoff is clearly signed and easy to find. From the turnoff, a rough dirt road heads up to the rock art area. The trailhead is clearly signed and is also easy to find. However, the access road has deep ruts filled with very fine sand. All terrain or at least high clearance four-wheel-drive is need to reach the trailhead.
GPS for the trailhead: 39.055376, -112.508980
You can see some rock art images from the trailhead. Walk up the hill to the lava rock and search around for more. It is worth spending an hour or two examining the boulders for rock art.
This is dry Great Basin desert landscape. It gets very hot during the summer. Winter days are often mild but winter nights can be bone-chilling cold. The dirt access road may not be after storms.