Opportunities for recreation in the area changed after the dam was built. Before the dam, people could hike or raft down secluded river canyons, explore archeological sites, fish for native species in the river, and observe wildlife in natural habitats. Much of the area was hard to get to, requiring long drives over rough roads or days of hiking. The area received few visitors.

Now, Lake Powell has over 2.5 million visitors every year. Tourism is the main source of income in the area. Roads provide access to several launching points around the lake, and people use speedboats, houseboats, and personal watercraft to explore the canyon walls that are still exposed above the water line. People can fish for trout and other introduced species, camp near the lake shore, explore the dam's visitor center, take scenic drives, and stay in air-conditioned hotels.

The increase in the number of visitors to the area indicates that more people now participate in recreation in the area of Glen Canyon. More visitors put a heavier demand on the natural resources though, and wastes and by-products of human recreation accumulate in the lake and along its shore.

2. Describe environmental costs associated with human recreation at Lake Powell.

Consider how opportunities for recreation in the area changed after the dam was built. Do you think the dam has proven to be a cost (negative effect) or a benefit (positive effect) in terms of providing opportunities for recreation? In the chart on your student answer sheet, use a scale from -2 to +2 to indicate your evaluation of the dam's impact on recreation.

A rating of -2 would mean that you believe the dam had a very negative effect on recreational opportunities in the area. A rating of +2 would mean that you believe the dam had a very positive effect on recreational opportunities in the area. A rating of zero would mean you thought the costs of the changes in opportunities for recreation were equal to the benefits.