ELY, Minn. (AP) -- Forest Service officials have temporarily banned campfires in the Superior National Forest,  including the Boundary Waters Canoe Area Wilderness, and closed some lakes and access points because of four wildfires burning in the area.

The Minnesota Department of Natural Resources is reporting high or very high wildfire danger across most of northern Minnesota. The Delta fire is the largest and is burning south of Snowbank Lake about 19 miles east of Ely.

Officials estimated it at 62 acres in size and believe it was caused by lightning.

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LOOK: Stunning vintage photos capture the beauty of America's national parks

Today these parks are located throughout the country in 25 states and the U.S. Virgin Islands. The land encompassing them was either purchased or donated, though much of it had been inhabited by native people for thousands of years before the founding of the United States. These areas are protected and revered as educational resources about the natural world, and as spaces for exploration.

Keep scrolling for 50 vintage photos that show the beauty of America's national parks.

LOOK: See how much gasoline cost the year you started driving

To find out more about how has the price of gas changed throughout the years, Stacker ran the numbers on the cost of a gallon of gasoline for each of the last 84 years. Using data from the Bureau of Labor Statistics (released in April 2020), we analyzed the average price for a gallon of unleaded regular gasoline from 1976 to 2020 along with the Consumer Price Index (CPI) for unleaded regular gasoline from 1937 to 1976, including the absolute and inflation-adjusted prices for each year.

Read on to explore the cost of gas over time and rediscover just how much a gallon was when you first started driving.