Although mountain lion or cougar attacks on humans are extremely rare, there are some commonsense precautions that you can take to reduce the risk even further.

1. Avoid areas where mountain lions have been seen frequenting.

2. Reduce food availability on your own property by making sure trash and other foodstuffs are secured.

3. Whenever possible, walk with a partner or small group when entering mountain lion country.

4. Be observant. Regularly look behind you, as a mountain lion will normally stalk you from behind.

5. Carry a strong walking stick or other weapon that is suitable to defend yourself.

6. If you find yourself encountering a mountain lion, try to make yourself look bigger. Wave your arms, yell, stand tall, and open your jacket up. By looking larger, the lion may find that attacking you is more trouble than it is worth.

7. Don't run. This may engage the flight response on the part of the mountain lion, and he will chase you down.

8. If attacked, fight back. Attack the lion's eyes, if possible, to inflict as much pain as you can.

Many states have developed educational programs on avoiding mountain lion encounters (e.g., in California, Keep Me Wild). In addition, perhaps the most comprehensive book on the issue of lion attacks on people is The Beast in the Garden by David Baron (The Beast in the Garden).

Other online resources:
Mountain Lion Control