Six Flags Discovery Kingdom: Coasters, Zoo & Hours

There aren’t many places where you can go from a floorless coaster to a dolphin show in the same afternoon. Six Flags Discovery Kingdom in Vallejo, California is one of them — a 135-acre park that blends thrill rides with a fully accredited zoo and marine-life park.

Location: Vallejo, California, off Interstate 80 ·
Size: 135 acres (55 ha) ·
Attractions: 60+ including roller coasters, animal exhibits, and marine life shows ·
Roller coasters: 8 (as of 2025) ·
Tallest coaster: Joker — 150 ft (46 m) drop ·
Opened: 1986 (as Marine World Africa USA)

Eight coasters, one pattern: this park’s coaster lineup favors variety over quantity, offering everything from launched rides to family-friendly loops.

What is the tallest roller coaster at Six Flags Discovery Kingdom?

How tall is Joker at Six Flags Discovery Kingdom?

• The Joker stands at roughly 100 feet (30 m) tall, according to secondary references, though older sources cite about 94 feet (29 m) for the prior wooden version (Wikipedia entry for The Joker).
• Its drop is listed at 150 ft (46 m), making it the park’s tallest drop (Six Flags Discovery Kingdom official ride page).
• The Joker is a Rocky Mountain Construction hybrid coaster that opened in 2019 after the former Roar wooden coaster was reworked (Wikipedia entry for The Joker).

What is the drop height of Joker?

• The Joker’s listed drop is 150 ft (46 m), the tallest in the park (Six Flags Discovery Kingdom official ride page).
• Its speed is commonly listed at 50 mph on secondary references (Wikipedia entry for The Joker).
• The minimum height requirement to ride is 48 inches (Six Flags Discovery Kingdom official ride page).

The implication: if you’re after the tallest drop in the park, The Joker is your target — and it requires riders to be at least 48 inches tall to ride.

How many roller coasters are at Six Flags Discovery Kingdom?

List of all coasters at Discovery Kingdom

• The park has 8 roller coasters (Wikipedia entry for Six Flags Discovery Kingdom):
• Joker (hybrid coaster, 150 ft drop)
• Medusa (floorless coaster, often considered the most intense)
• Superman: Ultimate Flight (launched coaster, high speed)
• Boomerang (inverting coaster)
• Kong (suspended coaster)
• Sidewinder Safari (family boomerang)
• Cobra (family coaster)
• Road Runner Express (junior coaster for kids)

Which coasters are for kids?

• Road Runner Express is a junior coaster with a lower height requirement (Six Flags Discovery Kingdom attractions page).
• Cobra is a family coaster suited for younger riders.
• Sidewinder Safari is a family boomerang that offers mild inversions.

The pattern: Discovery Kingdom’s 8 coasters are split roughly evenly between thrill-focused and family-friendly, making it a park that works for mixed-age groups.

What is the most intense ride at Discovery Kingdom?

Which ride has the highest G-force?

• Medusa is a floorless coaster that reaches speeds of 60 mph and includes seven inversions, often cited as the park’s most intense (Six Flags Discovery Kingdom official Medusa page).
• Superman: Ultimate Flight is a launched coaster that accelerates from 0 to 73 mph in seconds, delivering high G-forces at launch (Six Flags Discovery Kingdom official Superman page).

What is the fastest ride?

• Superman: Ultimate Flight reaches a top speed of 73 mph, making it the fastest coaster in the park (Six Flags Discovery Kingdom official Superman page).
• The Joker reaches 50 mph, while Medusa reaches 60 mph.

The trade-off: if raw speed is your metric, choose Superman. If you want a sustained adrenaline experience across multiple loops, Medusa is the better pick.

What are Six Flags Discovery Kingdom’s hours?

How to check hours for specific days?

• The official park hours page is maintained by Six Flags and updated regularly (Six Flags Discovery Kingdom official park hours).
• Hours vary by season and holiday — the park is typically open weekends in the off-season and daily during summer.
• The official park map also includes operating hours for specific zones (Six Flags Discovery Kingdom park map PDF).

Are hours the same year-round?

• No — the park operates seasonally, with extended hours from June through August and reduced weekend-only hours from September through May (Six Flags Discovery Kingdom official park hours).
• Major holidays (Thanksgiving, Christmas) may have special hours or closures.

What this means: the only reliable way to plan your arrival is to check the official hours page the day before your visit — third-party aggregators often lag behind the park’s seasonal schedule.

How does Six Flags Discovery Kingdom compare to other Six Flags parks?

Unique features of Discovery Kingdom

• Discovery Kingdom is the only Six Flags park with a zoo and marine-life park integrated into the same admission (Six Flags Discovery Kingdom Seal Cove experience).
• The park offers animal exhibits including Seal Cove (sea lions and harbor seals), giraffe feeding, a tiger exhibit, and a shark encounter (Six Flags Discovery Kingdom experiences page).
• It brands itself as the “Thrill Capital of Northern California” (Six Flags Discovery Kingdom home page).

Animal exhibits vs. thrill rides

• The park’s animal experiences include marine mammal shows (dolphins, sea lions), a giraffe feeding station, and a shark encounter (Six Flags Discovery Kingdom experiences page).
• This makes it a hybrid attraction — not fully a theme park in the Magic Mountain mold, nor a standalone zoo. It sits in a category of its own among Six Flags properties.
• The park is smaller than Six Flags Magic Mountain (which has 20 coasters to Discovery Kingdom’s 8) but compensates with its diversity of attractions (Wikipedia entry for Six Flags Discovery Kingdom).

Why this matters: for anyone visiting Northern California with mixed-age groups, Discovery Kingdom is the only major attraction where one member can ride Medusa while another watches a dolphin show — without driving to a second destination.

“The Thrill Capital of Northern California”

— Six Flags official website

“Originally opened as Marine World Africa USA in 1986, the park was acquired by Premier Parks (later Six Flags) in 1997 and renamed Six Flags Discovery Kingdom in 2007.”

— Wikipedia history section