“The Great American Novel” is a term that gets thrown around a lot, often referring to some possibly unattainable masterwork yet to be written. But there have been a number of Great American Novels written in the last couple of centuries, and “The Grapes of Wrath” is certainly high on that list. John Steinbeck’s Pulitzer Prize-winning 1939 novel is a heartbreaking, epic tale of a family of farmers driven out of Oklahoma by drought, dust storms and foreclosure and headed to California, lured by the promise of plentiful jobs, only to find more hardship and exploitation.

Now Ubuntu Theater Project brings Steinbeck’s masterpiece to the stage — or rather to Oakland City Church, where the company performed Marcus Gardley’s “The Gospel of Lovingkindness” in January.

The stage version is a Tony Award-winning script by Frank Galati, a member of Chicago’s Steppenwolf Theatre Company, which premiered the adaptation in 1988. Before this current production, the play was also produced in downtown Oakland five years ago by TheatreFIRST.

Performed in the church’s basement, Ubuntu’s production of “The Grapes of Wrath” is both bare-bones and large-scale, with an ensemble of 28 actors and a spare set of a lot of raw wood stools and pallets scattered around. Co-artistic director Michael Socrates Moran’s staging takes full advantage of the cavernous space, filling it with movement and sound. There are even a couple of key moments that take place behind the audience, where visibility is sometimes an issue.

There are a few shaky performances among the large cast, but the production is grounded by touching interpretations of the lead roles. Frequent Ubuntu performer William Hartfield makes a powerful figure as Tom Joad, a fiery young man who has to watch his temper amid all the injustice and suffering his family experiences. Co-artistic director William Thomas Hodgson plays the philosophical ex-preacher Jim Casy with a sort of folksy, thoughtful forthrightness faintly reminiscent of Jimmy Stewart.

Shannon Veon Kase is a tower of strength and warmth as Ma Joad, who works hard to keep the large family together on the road, including the indecisive Pa (jovial Dorian Lockett), incorrigible Grampa (a rascally Abe Bernstein), pious Granma (feisty Tamar Cohn), guilt-plagued Uncle John (a pensive Myers Clark) and Tom’s several siblings: possibly brain-damaged Noah (a sympathetically addled Francisco Arcila), womanizing youngster Al (Evan Feist, impish and sometimes difficult to understand), young child Ruthie (silent Luna Scott-Chung) and pregnant Rose of Sharon (Noelle Viñas, besotted with big dreams, alternating in the role with Christine Jamlig) and her weak-willed husband (a wavering Erik-Jon Gibson).

The journey is peopled with a seemingly endless array of cynical profiteers, desperate fellow travelers, brutish strike-busting goons and callous bosses. J Jha has a particularly haunting scene as a man crazed with grief who’s already been to California and found conditions there worse than the ones he fled in the first place.

It’s a story told on a grand scale, and everything is played very large in the Ubuntu production, full-voiced and theatrical. There are a number of pieces of visual shorthand that are wonderfully effective, such as the way a clump of people represent the Joad truck with only a few props, or the way death is represented by the characters slipping off their shoes and walking away.

The music directed by Tommy Crawford is especially forceful and resonant throughout, with haunting, propulsive renditions of spirituals and other folk songs performed a cappella by the ensemble, with plenty of stomping and lurching — work songs for those who want more than anything to find steady work. It’s a powerful portrayal of an awfully dark time in our nation’s history that can’t help but bring to mind how many of its ills aren’t over yet.

Contact Sam Hurwitt at shurwitt@gmail.com, and follow him at Twitter.com/shurwitt.