Frontier Airlines is slowly becoming a company with one of the most nonstop destinations from Las Vegas, after announcing plans on Tuesday to add four routes from Harry Reid International Airport.

The Denver-based ultra-low-cost carrier said it would begin flying daily routes to and from Baltimore, Maryland; Buffalo, New York; Hartford, Connecticut; and Kansas City, Missouri, beginning Aug. 9.

The new destinations will bump up the total number of cities served to 57 – only Southwest Airlines (63 cities) and Allegiant Air (61 cities) have more destinations. Las Vegas is the third busiest destination in Frontier’s system behind Denver and Orlando, Florida.

“Frontier Airlines continues to expand from Las Vegas,” said Daniel Shurz, senior vice president of commercial at Frontier.