MGM is preparing to erect the first new structure of its $950 million Springfield casino.

Crews have been clearing the roughly 14-acre development site in preparation for building a new parking garage. Foundation work on the seven-level, 3,400-space structure is expected start this week.

The garage will be completed in about 20 months. The casino, hotel and entertainment complex is slated to open in late 2018.

It’s one of three resort casinos in development in Massachusetts. Wynn has halted work on a $1.7 billion Boston-area resort, pending a challenge to its state environmental permit.

The Mashpee Wampanoag tribe’s $1 billion First Light resort is under construction and expected to open in part by 2017.