This 151-foot Washington waterfall drops directly under I-90, and the hike to see it is under two miles
Most people driving I-90 over Snoqualmie Pass have no idea a 151-foot waterfall is dropping right beneath them. Franklin Falls sits wedged between the highway’s east and westbound lanes, with the westbound side crossing a talus slope on a viaduct directly above the falls.
The trail to see it barely counts as a workout. It’s about 2 miles round trip with roughly 337 feet of elevation gain — easy enough that the Forest Service expanded the trailhead’s parking lot in 2023 just to keep up with how many people show up.
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The falls actually drop in three separate tiers, and only the bottom 85 feet of it is visible from the viewing spot on the trail. The uppermost tier starts as a 12-foot cascade through tall timber, tips into a second drop that veils 26 feet into a green-tinted pool, then squeezes through a narrow gap in the cliff and plunges 110 feet to the base.
Flow swings hard with the season. During peak snowmelt, the river can run twenty times its late-summer volume, blasting the lower tier outward off the cliff in a wide arching plume.
By August and September, it settles into something closer to a mountain brook, and the pool at the base turns into a genuinely good — if cold — swimming hole. This is exactly that window.
Getting there: take I-90 to Exit 47, then follow Denny Creek Road (Forest Service Road 58) about 2.8 miles to the parking area. It’s one of the most popular trailheads on the entire I-90 corridor, right next to the Denny Creek and Asahel Curtis trailheads, so a summer weekend morning is the move if you want an easy parking spot.
The trailhead sits on Mount Baker-Snoqualmie National Forest land, so you’ll need a NW Forest Pass — $5 for the day or $30 for the year. There’s an automated fee machine on-site if you don’t already have one.
Do you stop at the viewing platform, or keep working your way down toward the pool? Either way, this is about as much waterfall as you can get for as little effort as Washington offers.
Rules and fees change — always confirm current requirements before you go.
