Thunder Mountain Lakes are found in the Alpine Lakes Wilderness. The area is increasing in popularity, and the lakes are set in a highly sensitive area, so it is important to practice Leave No Trace principles should you decide to visit.
It's a hard trip because there's no official trail and the route requires scrambling with some exposure and navigation skills to weave through the rocks and cliffs. Remember the area is extremely fragile. Even with limited visitation there are many social trails around the lakes and areas like this are slow to recover from human impacts.
Be sure to only travel and camp on durable surfaces and pack out all your trash.