Participation in outdoor recreation activities continues to grow in Iowa. Iowans, like many other Americans across the country, continue to visit recreation areas and use available facilities at unprecedented levels. Much of this growth is related to and perhaps a direct result of increasing population, real income, leisure time, paid vacations and educational levels. However, other factors also come into play, e.g., facility development` advertising, highway construction, people mobility, technological changes, and changing individual tastes and preferences.