The bikers stood their ground, even using a bike as a weapon at first. This was a determined lion. Most attacks in WA end as soon as the person puts up any kind of resistance. One mom snatched her little one from the jaws of a cougar after pummeling it with a water bottle. Puma-ling.
http://www.khq.com/story/11079274/officers-tracking-cougar-that-reportedly-attacked-child

There has been an increase in Mt Lion attacks in Washington State in the last 20 years. When the lion population gets too dense, the young starving lions get more desperate. They speculate this one was so hungry it wouldn't give up. Some methods of lion hunting, and numbers allowed to be taken, have been reduced in recent years in WA state. Some think this may be having the effect of an increase in attacks. Others say less hunting makes for more stability.

Pepper spray has worked for one biologist we met presenting wildlife information a cub scout camp. On three occasions he said.

Yelling worked in this situation
http://www.spokesman.com/blogs/outdoors/...-while-camping/

Mt Lion hunters can legally use smaller caliber centerfire cartridges for taking than deer hunters can in WA state. 22 caliber for lion, 24 for deer minimum.