A bipartisan group of state representatives in Arizona is pushing mandatory ATV registration.  From the Arizona Daily Star [1]:

The measure would create a $20-$25 annual fee for each off-highway vehicle to maintain and build trails, restore damaged areas, educate riders and provide more law enforcement.

It also would make certain activities misdemeanors, including driving off paths in a manner that damages wildlife, property or natural resources. 

A bipartisan group of co-sponsors and a diverse coalition ranging from off-roading groups to environmental organizations supported the original bill, saying it would help protect landscapes and preserve the pastime in Arizona. 

 Let's hope that the house and senate make this bill become law.  If you live in Arizona, please contact your elected officials and tell them to support ATV registration.  You can find who your elected officials are here [2].