Highways Impact

Part of the Ecology Disrupted Curriculum Collection.

Southern California Highway
Southern California Highway


Download the files below to use offline, or to incorporate into your own lesson planning tools.

Highways Impact slide show


Highways Impact teacher's guide





This slideshow provides background information on the human motivation for building large highways in the region occupied by the bighorn sheep.


Key Idea: Highways are important to the tourist economy of Las Vegas.

Use the map of major roads and highways of the same region to introduce why highways are important to the Nevada economy.

  1. About 50,000 tourists a day arrived from California on Interstate 15 just in the month of July!
  2. If those numbers hold steady, Las Vegas will have over 18 million tourists a year arriving from California by car.  Almost half of all tourists to Las Vegas arrive by car from California.
  3. Also, the tourism economy employs over 260,000 people in Las Vegas alone, which is 30% of the working population.
  4. Tourists contribute billions of dollars to the Nevada economy, which helps to fund schools, museums, and city services.

Key Idea: There are many potential ways that highways can impact the bighorn sheep or other wildlife.

Use the picture of the Bighorn sheep and highway to connect the highways to the study.

Question: Scientists became curious about whether the highways that are so important to the Vegas economy were impacting the sheep.  Can you think of possible ways highways might impact living things that live near you? What are the consequences?
Answers:  Cars going at high speed run over animals on the roads; an increase in driving leads to increased emissions and air pollution; cars are loud and can scare away wildlife, etc. Some consequences are disrupted populations that are cut off from each other, diminishing wildlife populations, asthma and other environmental health problems for humans, etc.

Key Idea: Humans try to limit road kill by putting up fences.

If students suggest that these roads lead to increases in road kill, point out the fence on the next image. Fences are designed to limit accidents and road kill on the highways.

Question:  What do you notice about this picture?
Answer:  Humans have put up a fence between the highways and the terrain.

Question:  Why do you think the fences were put up?
Answer:  To protect people and their cars from damage occurred when running over animals while driving at high speeds.