Denver is ready to start spending millions of dollars to fill gaps in sidewalks around the city.

The city’s elected officials on Monday approved six different on-call contracts worth $3 million each to contractors that will build sidewalks over the next three years.

In all, Denver is missing 355 miles of sidewalks, according to city estimates. The city set aside $47.7 million to fill in gaps with its recent bonds package.

The project includes a focus on Globeville, Elyria and Swansea. The city also is focusing on sidewalks near transit stations (within 300 feet of train stations and 100 feet of bus stops) and along Sheridan Boulevard between Colfax and 17th avenues.

The contractors approved on Monday are Fasick Concrete; Halcyon Construction; Interlock Construction; Keene Concrete; Silva Construction; and Sky Blue Builders.

Separately, the city is mounting a sidewalk repair program that will force property owners to repair damaged sidewalks alongside their properties. That program will make discounts and low-interest loans available, depending on people’s incomes. It will start in central Denver this year.

In all, it could take an estimated $1 billion to complete the sidewalk network.