Crater Lake National Park

Crater Lake fills the caldera of Mount Mazama, a 12,000-ft Cascade volcano that collapsed during a catastrophic eruption 7,700 years ago. The lake is the deepest in the United States (1,943 ft), one of the deepest in the world, and the cleanest large body of water on the planet by measured clarity (sometimes exceeding 130 ft). It has no inflow or outflow — every drop comes from snow and rain falling directly into the basin. Designated a national park in 1902 (the fifth in US history), the park preserves 183,000 acres around the rim. From I-5 the standard route is Exit 30 in Medford, OR, then 80 mi northeast on OR-62 to the Annie Spring Entrance at the south end of the 33-mile Rim Drive. The North Entrance from US-97 closes with the first major snow each fall.

• Deepest lake in the United States (1,943 ft) — ninth-deepest in the world
• Among the cleanest natural large lakes on earth (clarity often > 130 ft)
• Filled the caldera of Mount Mazama, which collapsed in a 7,700-year-old eruption ~42 times the magnitude of Mount St. Helens 1980
• Fifth-oldest US national park (designated May 22, 1902)
• No inflow or outflow — water level maintained entirely by precipitation and evaporation

• Rim Drive (33 mi loop with 30+ overlooks)
• Crater Lake Lodge on the rim
• Cleetwood Cove Trail (the only legal lake-access trail)
• Wizard Island boat tour (when running)
• Watchman Peak summit hike

Best months: July through September — full Rim Drive open, both visitor centers staffed, all overlooks accessible.

Closures: Rim Drive typically closes with the first significant snow (early November) and the North Entrance / North Junction Road close at the same time. They reopen as plowing allows, usually mid-June to early July. The South Entrance road from OR-62 is plowed all winter.

Notes: Crater Lake averages 41 feet of snow per year at the rim — among the snowiest places in the contiguous US. Even in July, snowbanks can persist at trailhead level.