There’s a rollicking Wild West adventure buried deep inside The Lone Ranger, a bloated, mega-budget revival of the story of the iconic gunslinger and his Native American sidekick Tonto. The movie is a spirited entertainment whenever it manages to take flight, such as in two enormous action sequences that bookend the film set aboard speeding locomotives, or the occasional comic exchanges between the masked hero (a square-jawed, endearingly earnest Armie Hammer) and his bizarro mystical partner Tonto (Johnny Depp in subdued oddball mode, buried under pancake makeup and wearing a dead bird on his head as a hat). When The William Tell Overture, the Ranger’s theme song since his radio days in the 1930s, finally blares on the soundtrack after being sneakily withheld for much of the picture, the effect is so rousing that you levitate in your seat a little bit.

But the rapture never lasts long. Director Gore Verbinski and producer Jerry Bruckheimer have adopted the more-is-better approach they used in the Pirates of the Caribbean series in The Lone Ranger, crowding the movie with so many extraneous characters and irrelevant subplots that the film becomes an endurance test dotted by patches of fun. There are not one but three villains — a scheming railroad baron (Tom Wilkinson), a murderous outlaw (William Fichtner) and a corrupt U.S. marshal (Barry Pepper) — who inflate the script with scenes of knotty, dull exposition. The story is narrated in flashback at a diorama exhibit by an aged Tonto to an entranced little boy, and every time the movie cuts away from the action and back to the kid, the pacing stalls. There’s no purpose to the narrative device other than to allow an unrecognizable Depp to perform in old-man makeup.

There are also two female characters (Ruth Wilson as the Ranger’s sister-in-law and Helena Bonham Carter as a one-legged brothel madam) who are here for no apparent reason other than to keep the movie from being an all-boys show. Carter’s scenes in particular cry out to be excised: Her fake leg, which is made out of porcelain and harbors a secret shotgun, is a beautiful prop that the filmmakers obviously adore. But there’s no room for such indulgences in a movie that already runs a punishing 2 1/2 hours.

Made at a reported cost of a whopping $250 million, The Lone Ranger certainly looks wonderful, with beautiful John Ford-style vistas, a score inspired by Ennio Morricone and action set pieces that minimize the use of CGI whenever possible. The film is also tinged with subtle touches of fantasy (the rumored werewolves never appear, fortunately, but there are some carnivorous bunny rabbits).

But the tone is all over the place, wildly veering from broad comedy to surprisingly dark horror — a sign there was never a guiding vision behind the picture other than a movie poster and Depp’s bankability. And for all its attempts at historical relevance (the story explores everything from the exploitation of Chinese workers to build the railroads to Native American genocide), there’s no gravity or weight to anything in The Lone Ranger. Everything is flung at you at the same pitch and speed, at times relegating the two heroes to supporting characters in their own adventure. Hammer and Depp make an appealing pair — they have genuine chemistry, and they’re funny and likable together — but they deserved a movie that matched their personalities. This plodding, overwrought picture isn’t it.