The Arizona Department of Transportation, the Arizona Game & Fish Department and the Arizona State Parks Board are required to conduct a study every three years on watercraft fuel consumption and recreational watercraft usage. The fuel consumption data is collected to determine the allocation of motor vehicle fuel tax to the State Lake Improvement Fund. The information on recreational watercraft usage patterns on Arizona’s lakes and rivers is necessary, in part, to determine the distribution of SLIF funds to applicants.

Apache trout is a federally threatened salmonid native to headwaters of the Little Colorado, Black, and White rivers in east-central Arizona. Decline of Apache trout to threatened status was attributed to over-fishing, habitat degradation and negative interactions (predation, competition and hybridization) with introduced nonnative salmonids. Although over-fishing is no longer considered a threat, habitat degradation and negative interactions with nonnative salmonids continue to threaten Apache trout, and it is towards these threats that recovery actions are directed. While barrier construction began in 1979 and livestock exclusion began in the mid-1980s, the efficacy of these recovery actions at increasing Apache trout abundance and improving habitat condition had not been evaluated. We therefore initiated a study to evaluate the efficacy of riparian fencing and barriers.