There have been many claims about the growth of OHV recreation.
The attached file is a news release from the Forest Service citing statistical data that supports that statement.
In general, note:
2000 - 17.6% of the population (37.6 million)
2002 - 19.3% of the population (41.4 million)
2004 - 23.2% of the population (49.6 million)
And, there are claims that access to wheeling areas is decreasing.
These numbers, along with US Census data about population trends, is important as we move into the future.
This data will be driving policy changes that will affect your recreation opportunity.