"My friends, it is springtime in Alberta, and a fresh wind is blowing," the NDP leader told the crowd after she and her 11 cabinet ministers took their oaths.
"Today we open up a new chapter in the story of Alberta."
It was a festival atmosphere under sunny skies amid sticky heat alleviated only by the occasional gust of wind.
There were kids and adults. Some stood in the reflecting pool to watch. They came in shorts, swimsuits and sunhats.
They ate free ice cream, chanted "Rachel! Rachel! Rachel!" and roared in approval when it was announced former premier Jim Prentice and his Progressive Conservative government had resigned.
Afterward, the New Democrat elected members and cabinet ministers waded into the crowd to shake hands and pose for pictures.
"It really is about opening up this legislature and ... making the government of Alberta meaningful to Albertans again," Notley told reporters.
Former Calgary alderman Joe Ceci was named the new finance minister at the ceremony. Former teacher and school administrator Marg McCuaig-Boyd was posted to energy. Former NDP leader Brian Mason is the new minister of infrastructure and transportation.
The ceremony brought to a close 43 years, eight months, and 15 days of Progressive Conservative rule. It is the longest stretch of power by one party in Canadian history.
Notley's team made its own history on May 5, capturing 54 of 87 legislature seats to dethrone the Tories. It's the first NDP government in Alberta.
It is also a passing of the torch.
Notley's father, Grant Notley, was the leader of Alberta's NDP during lean years for the party in the 1970s and early 80s. He died in a plane crash in 1984, just two years before the NDP made an historic breakthrough, winning 16 seats and forming official Opposition in 1986.
Notley ran on a plan that includes higher income taxes for the wealthy and rolling back many of Prentice's proposed tax and fee hikes.
She has promised a review of oil royalties, to hike the minimum wage to $15 by 2018, to fund thousands of new grade-school students arriving this fall, and to balance the budget by 2018-19.
The NDP hopes to put behind it a difficult week of transition.
On Friday, the party apologized for using online invitations to the taxpayer-funded swearing-in as a way to raise funds. It also ejected rookie member Deborah Drever following the circulation of a series of questionable photos. The 26-year-old will sit as an Independent.
The ceremony launches a busy schedule.
The cabinet will hold its first meetings, in Calgary, on Wednesday and Thursday.
The legislature resumes on June 11 for the selection of a new Speaker. There will be a speech from the throne on June 15 followed by a short session mainly to pass a bill to keep the province's money flowing while Notley's team crafts its first budget to be released in the fall.
The election has radically redrawn the legislature seating chart.
The Tories have been reduced to just nine seats. The Wildrose party captured 21 seats to remain the Official Opposition. David Swann, the interim leader of the Liberals, is now the party's only legislature member. Greg Clark, leader of the Alberta Party, won for the first time in Calgary Elbow.
Prentice's seat is the lone vacancy.
He quit politics on election night.