http://www.xmission.com/~jbdaniel/topazmtn.htm
If you plan on going to Topaz Mountain, take plenty of water, make sure you have a spare tire and the means to change it, food, first aid kit, and a full tank of gas. Cell phones don't work out in the desert so take what ever you will need and be prepared. Respect the gravel roads and don't travel too fast or you will loose control of your vehicle and it could be very ugly.
Winter is an excellent time to visit the Thomas Range because these mountains receive very little snow and the temperatures on average are warm enough to do some rock hounding in relative comfort. Lastly, if you are not familiar with the Desert, make sure that you are not caught on the unfamiliar roads after dark because it is very easy to get lost out there. Visiting Topaz Mountain and the Thomas Range can be quite an adventure, but it is worth the effort if rock hounding is an interest that you have.