Visitors to the just-completed High Line at the Rail Yards park can now walk continuously from Gansevoort to 34th streets, taking in vista views of city life below, the Hudson River and landscaped greenery along decommissioned rail tracks.

The elevated park's $35-million expansion, which opens this weekend, is the project's third and final phase -- the culmination of years of planning, lawsuits, fundraising, construction, landscape architecture and a dream by two men.

Where a bustling rail line once choo-chooed from 1934 to 1980 along Manhattan's westernmost stretches, bringing meat to the Meatpacking District, now stands a 1.45-mile wonderland of trees, grasses, shrubs and perennials free and open to the public.

"At one time it connected the West Side with meats and fresh fruits," said City Councilman Corey Johnson, who represents the area. "Now, it's connecting the West Side with people and children and seniors."

The High Line's first section, spanning Gansevoort to West 20th Street, opened in 2009, and on Saturday politicians and the two men who dreamed up the idea for the park, locals Joshua David and Robert Hammond, cut a ceremonial ribbon to open the final section, the northernmost part, that goes from West 30th Street and 10th Avenue to 12th Avenue and then to 34th Street.

More than 4 million people have visited the park since it opened five years ago, park officials say.

The expanded section officially was to open Sunday, but the public was being let in beginning Saturday afternoon, High Line spokeswoman Jennifer Pastrich said.

The High Line almost didn't happen. In the 1980s, owners of nearby property tried to get demolished the structure where the park now stands, but activists successfully fought those plans, and it remained unused and in a state of disrepair for years. Then, in 1999, David and Hammond conceived the idea for the park that would become the High Line.

It's now maintained mostly through the private Friends of the High Line, but managed together with the New York City Department of Parks & Recreation.