Four times a week, an Allegiant airplane ferries almost 150 people between Rapid City and Mesa, Ariz., for as little as a $39 base price for a one-way ticket.

That's cheap transportation - perfect for college students on a budget. Carl Niemann, 19, of Custer, was taking the Allegiant flight Saturday from Rapid City to Mesa, Ariz., because he was headed back to Tempe for college, where he studies game design.

"It's a direct flight, so there's no hub transfers. So, it's actually quicker. I like it because it's near my school."

"I've seen a few people take Allegiant to here. I know two other people that are going to college in Arizona, so they're taking Allegiant all the time," he said.

And for people with family in Arizona, it offers an inexpensive way to visit. Matt McGillivray of Arizona said he used the flight from Mesa to Rapid City to see his family.

"They live up in Spearfish and Newell. It's very inexpensive, and there's no stops along the way."

McGillivray said he knows of other Arizonans who use the service. "I know a lot of people; they have family up here."

The travel goes both ways. Jon and Joanne Nelson of Rapid City were taking an Allegiant flight on Saturday to Mesa.

Joanne Nelson said, "We have relatives there that we're going to spend a long weekend with." She said her family uses the route to visit the Hills, as well. "It's a fantastic flight. Usually, they see anything they want to. They ride around on a Harley in the Hills, and they enjoy the sights."

The service began two years ago as part of the Las Vegas-based airline's expansion among small northern cities, and by every measure, it's considered a success, with Allegiant the rare airline operating in the black because of an unusual business model.

Now, tourism officials in both cities are hoping to capitalize on the success, to give those 15,000 travelers even more ways to enjoy their destinations and spend money, whether it's at a Black Hills bed and breakfast or a saguaro-lined golf course.

Officials from Rapid City's airport and convention and visitors bureau met recently here with a representative of the Mesa Convention and Visitors Bureau to discuss ways to cooperate.

"Phoenix has a lot to offer people in Rapid City, and we certainly have a lot to offer people in Phoenix," airport director Cameron Humphres said. He said he wants to get the message out "that there are a lot of great things to do and see in the Black Hills, and hey, we're only a direct flight away - a very affordable flight away."

For starters, they'll link to each other's convention and visitors bureaus from the airport Web sites, and later, the Rapid City group hopes to develop more comprehensive travel packages in the Hills for visitors from the southwest to buy, Humphres said.

Rapid City Convention & Visitors Bureau director Michelle Lintz wouldn't discuss specifics but said she envisions "some kind of marketing down in his part of the country to actually bring people up from Mesa to Rapid City."

As would be expected, a majority of the summertime travelers on the flight originate in Mesa - people beating 115 degree heat by escaping to the Hills. Likewise, most people on the flight in the winter start in Rapid.

Allegiant offers comprehensive tour packages to northern residents heading south: Rapid City fliers who buy a ticket at www.allegiantair.com first have to navigate pages of offers for weekends at the Arizona Biltmore or tickets to Blue Man Group. That's part of Allegiant's unique business model, Humphres said.

"Allegiant Airlines is all about leisure travel. Their business model, they're a travel agency that, oh by the way, we also have an airline."

But as far as Allegiant goes, Mesa residents are on their own for figuring out to do once they step off a plane at RAP. That's where the convention and visitors bureau can come in.

Allegiant doesn't currently see Rapid City as a vacation destination, but Humphres hopes to change that.

"The Black Hills region is really becoming a really multifaceted tourist destination," he said, mentioning adventure tours, cycling, canoeing, and even relative proximity to Western icons such as Yellowstone National Park.

"If we can show them that they're missing out on some incremental business, that they're leaving money on the table, so to speak, in Rapid City, they're going to take notice."

Because of strong ridership so far, Allegiant boosted the number of weekly flights between the cities to three from two this summer, but is back to two for the fall.

Humphres hopes in time, the number will continue to expand.

Meanwhile, Hills residents who've taken the flight to Mesa as a cheap gateway to better-known destinations like the Grand Canyon might expect to see more pitches from Mesa itself - and not just those coming from Hohokam Stadium.

"Our mission is to put people in Mesa hotel rooms," marketing director Milt Fort said. "Heads in beds."

The visit to Rapid City, which he initiated as part of a tour of all Allegiant's destinations out of Mesa, was the first for Fort, who has lived in Arizona more than 50 years. He saw bison for the first time and planned trips to Mount Rushmore and other area attractions.

Now, he hopes people who've never been to Arizona will reciprocate.

"We've made it easier, we've made it cheaper for them."