SIOUX FALLS, S.D. (KELO) — The spruce tree tied to the top of a vehicle traveling down Interstate 90 in South Dakota could be a tree from the Black Hills National Forest.

“I have seen trees tied to cars on the interstate,” said Scott Jacobson, the Black Hills National Forest Public Affairs Officer. Jacobson said he’s not sure how far people travel to cut down a Christmas tree in the Black Hills. “People come from the regional area…,” he said.

The season to buy a tree permit to cut down a Christmas tree in the national forest has started. So, it’s possible a driver may see a vehicle with a tree tied to its top over the coming months.

The National Park Service sells about 5,000 tree tags a year, he said. The number may vary between 4,000 and 5,000 he said.

“That’s about 1,000 per district,” Jacobson said.

The national forest is divided into four districts: Bearlodge Ranger District, Northern Hills Ranger District, Mystic Ranger District, and Hell Canyon Ranger District. Permits are available for each district.

Trees can only be taken from designated areas in those forest districts.

Permits can be bought at forest service offices, online through the forest service and through private vendors. Permits are $10 but if ordered online, there is a $2.50 processing fee.

Custer Ace Hardware has been selling national forest tree tags for at least eight years, manager Cheryl Hadlock said.

“It goes very well,” Hadlock said. “We sell over 600 plus every year.”

Jacobson said the National Forest Service has been selling Christmas tree permits for at least 20 years.

“It’s a neat family tradition,” Jacobson said. When his children were young, Jacobson said his family participated in the tradition of cutting down a Christmas tree from the national forest.

Hadlock said the Custer Ace Hardware has a mix of traditional and new customers each year.

“Some cut one every year…,” Hadlock said. Others include new residents who are excited to cut a Christmas tree for the first time.

Tags sales increase after Thanksgiving. “That’s when we start getting busy with tags,” Hadlock said.

The Black Hills forest covers more than 1.2 million acres which is about 2,000 square miles. Within that forest are millions of trees, Jacobson said.

But not all are suitable for Christmas trees.

Permit holders can’t cut a tree more than 20 feet tall. Other requirements are a maximum six-inch stump height and a maximum stump diameter of six inches.

“Generally, the tree selected for a Christmas tree is a spruce,” Jacobson said. Spruce trees have a taper that resembles the traditional Christmas tree. The needles are also well-suited for hanging ornaments.

The spruce trees are usually found on north-facing slopes, Jacobson said. They are most often in shaded areas.

Permit holders will also cut ponderosa pines. Those trees have a full shape, and long, graceful needles, according to the forest service. Jacobson said these trees are found in more sunny spots.

Junipers are also selected for Christmas trees. These grow at lower elevation.

The National Forest Service offers plenty of help for would-be Christmas tree cutters including maps and tips for how to care for the tree when it arrives home.

Jacobson said weather can affect tree cutting, but in general, seasonal temperatures and snow don’t deter the tree cutters.

“If it’s seasonal and nice weather, the Saturdays are (busy),” Jacobson said.

The forest service does remind people they will be in the forest and winter clothing and an appropriate vehicle may be needed in pursuit of the Christmas tree. The tree-cutting season closes on Dec. 31.