More Visitors at Copper Rim: A National Park Road Trip

Use park records to argue how more people, and more visits per person, change a canyon park.

Part 1: More people, more visits

Read the passage and use Table 1 to answer questions 1–3.

Bumper to Bumper at the Canyon

1Every summer, eighth grader Mireille Okafor and her grandfather take a road trip to a national park. This July they drove to Copper Rim National Park, where a river has cut a canyon about 600 m deep through layers of red and white rock. Her grandfather first visited in 1990, and he remembered finding an open parking spot at every overlook. This time the line of cars at the entrance gate stretched for 2 km, and the canyon road was packed from morning to evening. At the most popular overlook, they waited twenty minutes for a parking spot and then shared the railing with dozens of other visitors.

2At an evening ranger talk, Ranger Benedikt Aranda shared some of the park's records. Most visitors come from cities and towns within a day's drive, and the number of people living there has grown. People in the region also visit more often than they used to. Many families now take short weekend trips, and photos of the park's famous viewpoints are shared widely online.

3Ranger Aranda described several places that the records track. Juniper Spring, the only spring near the visitor center that flows all year, supplies water for the restrooms, drinking fountains and campground. Below the spring, a small creek is home to a tiny snail found nowhere else. At Overlook Point, many visitors step off the paved path to take photos. Where the ground there is now bare, rain has cut gullies 20 to 30 cm deep since 2005, and sand has piled up in the dry wash below the point.

4The park also has an air monitor that counts "haze days," when tiny particles in the air keep visitors from seeing landforms 80 km away. Such particles come from smokestacks, engines and blowing dust, and they can drift hundreds of kilometers on the wind. The nearest large cities are about 300 km upwind of the park.

5In 2022 the park started a free shuttle. In summer, most visitors now park at the visitor center and ride buses along the canyon road instead of driving it. Table 3 compares the July before the shuttle began with a July after it began.

Table 1: Copper Rim Visits and the Region (rounded)
Year	People in region (M)	Visits per 1,000 people	Park visits (M)
1990	20	50	1
2005	25	80	?
2020	30	150	4.5

M means millions. "People in region" counts everyone living within a day's drive of the park. "Visits per 1,000 people" is how many park visits that region makes each year for every 1,000 people living there.

Park visits = people in region × visits per 1,000 people ÷ 1,000.

In 2005 the park had about million visits.

Suppose the region had grown to 30 million people by 2020, but people still made only 50 visits per 1,000 people, as in 1990.

The park would have had about million visits in 2020.

Compare your answer to question 2 with the real 2020 visits in Table 1. What does the comparison show about the rise from 1.0 million to 4.5 million visits?

A. Population growth and visiting more often each added about 1.75 million visits.
B. The rise came from visiting more often, since the region's population stayed near 20 million.
C. Most of the rise came from people visiting more often; growth alone adds 0.5 million.
D. Most of the rise came from population growth, since the region gained 10 million people.

Part 2: What the park records show

Use Table 2, the bar graph and paragraphs 3 and 4 to answer questions 4–7.

Table 2: Copper Rim Park Records
Year	Cars in per day (July)	Wildlife hit by cars	Haze days per year	Spring pumping (m³/day)	Spring snails counted
1990	1,200	4	20	40	900
2005	2,400	9	34	80	600
2020	5,000	21	52	160	250

"Wildlife hit by cars" counts deer, bighorn sheep, foxes and tortoises found hit on park roads in the whole year. Spring snails are counted each May in the same 10 m stretch of the creek below Juniper Spring.

Use the bar graph and Table 1. Compare 2020 with 1990.

The bare ground at Overlook Point grew to times as large, while the number of park visits grew to times as many.

Use paragraph 3 and the bar graph. Which explanation best links the trampled ground at Overlook Point to the new gullies and the sand in the wash?

A. Trampling killed plants whose roots held the soil, so rain carried loose soil downhill.
B. Haze particles settled on the ground and made the rain hit it harder, cutting gullies.
C. Pumping at Juniper Spring dried out the ground, so it cracked open into gullies.
D. Cars on the canyon road shook the ground, and the shaking slid sand down into the wash.

Mireille wants to argue that the growing number of visits is changing the park's living things (the biosphere). Circle each record that is direct evidence of a change in living things.

Wildlife hit by cars rose from 4 to 21 a year.Cars entering each July day rose from 1,200 to 5,000.Spring snails counted in May fell from 900 to 250.Haze days rose from 20 to 52 a year.Spring pumping rose from 40 to 160 m³ a day.

Use Table 2 and paragraph 3. Which pattern best supports the idea that heavier use of Juniper Spring is linked to the drop in spring snails?

A. The snail count fell most from 1990 to 2005, when pumping changed the least.
B. Spring pumping doubled in each period while the snail count fell in each period.
C. Spring pumping stayed near 40 m³ a day while the snail count fell from 900 to 250.
D. The snail count rose from 1990 to 2005, then fell as pumping rose after 2005.

Part 3: The shuttle and the next plan

Use Table 3 and the passage to answer questions 8–12.

Table 3: July Before and After the Shuttle
Record	July 2021 (no shuttle)	July 2023 (shuttle)
Park visits in July	600,000	620,000
Cars on the canyon road per day	5,000	3,000
Wildlife hit by cars in July	4	2
Haze days in July	7	6

Use Table 3.

After the shuttle began, the number of cars on the canyon road each day fell by %.

Which conclusion about the shuttle do the July records support best?

A. Visits fell by about 40%, and that is why fewer animals were hit on the road.
B. Visits rose a little, and more animals were hit, since buses are larger than cars.
C. Visits stayed the same, and haze days fell by half once buses replaced cars.
D. Visits rose a little, but driving on the canyon road fell, and fewer animals were hit.

10.

Use paragraph 4 and Table 3. Cars on the canyon road dropped sharply, but haze days barely changed. Which is the best explanation?

A. Haze is mostly water droplets from the river, so traffic has little to do with it.
B. Much of the haze likely drifts in from the growing cities upwind, which the shuttle does not change.
C. Particles from the 2021 cars stayed in the canyon air for two years, so the haze stayed high.
D. Buses give off more particles in total than the cars they replaced, so the haze stayed high.

11.

The park expects about 6 million visits a year by 2035. Which plan would most likely let more people visit while slowing harm to the park's land, water and wildlife?

A. Add shuttles and a fenced viewing deck at Overlook Point
B. Widen the canyon road to four lanes for faster traffic
C. Build a 2,000-space parking lot beside Overlook Point
D. Pump more water from Juniper Spring for new restrooms

12.

Mireille's grandfather says, "This park covers 1,900 square kilometers. A few million visitors a year cannot change its land, water, air or wildlife." Write an argument for or against his claim. Use at least three pieces of evidence from the tables, the bar graph and the passage, and explain how both the growing region and the way each person uses the park play a part.