A modest ledge drop on the upper Chehalis River inside a 129 acre camping park on the Willapa Hills Trail, best when the winter rains have the river up.
November through April
Big water window
in a typical year
Rain fed
What drives it
Chehalis River
Live USGS
Data on this page
gauge 12020000
WA State Parks
Managed by
their rules govern
Trail status, closures and safety rules belong to each falls' managing agency, named and linked on every page.
The season
What fills Rainbow Falls, and when
The upper Chehalis is a pure rain river draining low coastal hills, and the falls scales with it: a proper churn in the November through April wet season, a gentle slide over the ledge by late summer, when the gauge upstream at Doty can read one percent of its winter peaks. Expect a riverside park with a falls rather than a 200 foot spectacle.
Typical best flow: November through April
JFMAMJJASOND
What the agency itself says
Rainbow Falls State Park is a 129-acre camping park on the Chehalis River. A variety of campsites along a tranquil river setting make this a popular overnight stay for hikers, cyclists and horseback riders tackling the Willapa Hills Trail.
Gauge: USGS 12020000 Chehalis River near Doty WA, upstream of the falls on the same river. The gauge reads the river, not the brink of the falls, so treat it as the trend line rather than a turnstile.
Source: USGS Water Services (National Water Information System). Instantaneous values and daily statistics services. U.S. Geological Survey data are works of the United States Government and are in the public domain. Gauge verified 2026-08-27.
Multnomah Falls in autumn: a Columbia Gorge falls that keeps respectable flow year round, and the standard against which most falls seasons get measured. “Columbia River Gorge National Scenic Area Multnomah Falls, fall color - 3” — Forest Service Pacific Northwest Region — Public domain
Getting there
Access, in the agency's words and ours
The park serves hikers, cyclists and riders on the Willapa Hills Trail, per Washington State Parks. A 2007 flood took out the bridge that connected the main park to the trails across the river; trail parking is along State Route 6.
Rain-fed river falls run on the season's weather wherever they sit; this one is Blackwater Falls, West Virginia. The upper Chehalis keeps the same wet-winter, quiet-summer rhythm. “Blackwater Falls (15437499241)” by Benjamin Smith from United States, CC BY 2.0
Common questions
Rainbow Falls flow season FAQ
The reliable big-water window is November through April. The upper Chehalis is a pure rain river draining low coastal hills, and the falls scales with it: a proper churn in the November through April wet season, a gentle slide over the ledge by late summer, when the gauge upstream at Doty can read one percent of its winter peaks. Expect a riverside park with a falls rather than a 200 foot spectacle.
This page reads the USGS gauge on Chehalis River (Chehalis River near Doty WA, upstream of the falls on the same river) live in your browser, and shows the latest flow next to the median USGS publishes for today's date, so you can see where today sits in the year. The gauge reads the river, not the brink, so treat it as the trend rather than a turnstile.
The ledge never empties, but summer reduces the falls to a modest slide. Winter and early spring bring the version worth the detour, and the river's swimming holes belong to summer, with no designated swimming area or lifeguards, as the park notes.
Rainbow Falls State Park (Washington State Parks). The park serves hikers, cyclists and riders on the Willapa Hills Trail, per Washington State Parks. A 2007 flood took out the bridge that connected the main park to the trails across the river; trail parking is along State Route 6. Trail status, closures and safety rules are theirs, and their page is linked on this one; nothing here overrides what they publish.
In their own words: "There is no designated swimming area or lifeguards here." That sentence is Rainbow Falls State Park (Washington State Parks)'s, quoted verbatim, and their page is the place to check before you go.
Yosemite Falls in May, running on snowmelt that will be gone by late summer. The National Park Service tells visitors the falls can be dry by August, which is why every falls page here starts from its watershed. “Tourists below Yosemite Falls (39832011431)” by Mike McBey, CC BY 2.0
Flow windows are typical-year climatology drawn from the driver and the agency language quoted above, not forecasts. Live readings and per-date percentiles are U.S. Geological Survey data, public domain; the above-or-below-typical line is our comparison and is labelled as such. Access, trail and safety information belongs to Rainbow Falls State Park (Washington State Parks). National picture: waterfall season across the US → Hero image: “Blackwater Falls (15437499241)” by Benjamin Smith from United States, CC BY 2.0
Places to stay