This is a special day in the construction of San Francisco's tallest building. The support structure for the Salesforce Tower is now complete. Lifting the final beam into place is part of the ceremony known as "topping off" in the construction trades. That's what builders, financiers and future tenants were celebrating on Thursday at Salesforce Tower.

"The ceilings are the highest, the air is the cleanest, the natural light is amazing and the views are pretty good," Hines Commercial Real Estate spokesperson Paul Paradis said. He's right. From the East Bay to the Golden Gate Bridge, views from the 1,000-foot-tall building are stunning.

From the 60th floor of the Salesforce Tower, visitors can look down on the Transamerica Pyramid -- and that isn't even the top floor.

"There's almost no point in San Francisco that you can be in today without seeing this tower," San Francisco Supervisor Jane Kim said.

The anchor tenant will be Salesforce. CEO Marc Benioff says that means jobs. "We'll have 10,000 employees right here at this new Salesforce Tower campus," he said.

When completed, the new tower will be one of three Salesforce Tower buildings downtown. The developer of the $1.1 billion tower made sure people knew this skyscraper would not begin to settle and lean, like the 58-story Millennium Tower in San Francisco.

"So the mantra everyone should leave with today is bedrock baby. This building's in bedrock. It's not going anywhere," developer Robert Pester said.

It is 61 stories tall and if things are on schedule and they finish late this year, it should be ready for occupancy in early 2018.

Salesforce has special plans for the top floor. Benioff said that there would be no offices on the 61st floor. It will be open and employees can use it for meetings and gatherings on the week. On weekends, they'll let community groups use the top floor for free for their activities. He says it's them giving back.

San Francisco is locked into a race to have the tallest tower west of the Mississippi. The Salesforce Tower is the tallest in San Francisco at 1,072 feet. But it won't be the tallest in the state. That distinction will go to the new Wilshire Grand Tower in Los Angeles, which will rise to 1,099 feet. However, the Salesforce Tower will have the tallest occupiable floor.

In Seattle, an architecture firm is planning the West Coast's tallest building, the 4/C Tower, which is slated to be 1,111 feet. But the FAA is fighting the plan since it may interfere with airspace.