DENVER (CBS4) – It was 20 years ago Saturday that Stapleton Airport, Denver’s premier airport from 1929 to 1995, closed for good. Hours later takeoffs and landings shifted to Denver International Airport.

DIA was then and continues to be the progressive standard for airports for everything from transportation inside the terminal to forecasting outside.

READ MORE: Large Fire Erupts At Westminster Apartment Building; Federal Blvd. Partially Closed
Denver International Airport (credit: CBS)

Denver International Airport (credit: CBS)

There was a big celebration held Saturday for the airport’s 20-year anniversary that was attended by Denver Mayor Michael Hancock, Federal Aviation Administration Administrator Michael Huerta, airport CEO Kim Day, VIPs and others who helped build and run the airport.

DIA has gone from bringing in $3 billion to the Colorado economy in its first year to bringing in $26 billion every year. Officials say that number will keep rising.

“I remember when it opened and I remember when the caravan came over from Stapleton,” aviation enthusiast Steve Maddux said. “It seems like yesterday.”

“It doesn’t look 20 years old,” Denver resident Mick Collins said.

Collins was flying to London with his fiancé and daughter on Saturday.

“I’ve been around the world, and actually Denver is one of the best airports in the world — seriously,” he said.

READ MORE: Wongel Estifanos Died Due To 'Multiple Operator Errors' On Glenwood Caverns Adventure Park Ride

“I like how it’s really nice and spacious,” a young traveler told CBS4.

Known as the Gateway to the West, DIA has grown from serving 31 million passengers in 1995 to an all-time record 53.4 million passengers in 2014.

“When you take those numbers, including the 180,000-plus people employed through this airport’s activities, you begin to understand the true jewel that this airport is — not only for our city, our region, but the entire state of Colorado,” Hancock said.

The state’s largest economic driver also has some major milestones coming up.

Plans for the airport (credit: CBS)

Plans for the airport (credit: CBS)

“In November we’re going to be opening this hotel … and in the spring FasTracks will begin running, which will connect us to Denver Union Station on a 35-minute ride,” Day said.

“For us to make sure this airport thrives well into the future — for future generations — we have to do some serious changes,” airport spokesperson Stacey Stegman said. “That’s what we’re doing right now and trying to really be more cutting edge, more advanced, so we can continue to compete on the global stage.”

MORE NEWS: Grammy Award Winning Pianist Peter Kater
(credit: CBS)

(credit: CBS)

This year DIA is building an outdoor plaza for arts and entertainment. Also expect to see new seating, additional power outlets and more shops and restaurants.