I've had a lot of requests for a list of waterfalls that are good for kids.  For now I've only including waterfalls in Whatcom, Skagit, and Snohomish County.  In general, kids seem to enjoy a little bit of adventure and they like getting up close and personal with the waterfalls.  My list below contains a lot of smaller waterfalls and almost all of them involve some sort of adventure to get to, although it's generally a short adventure.  This is not a comprehensive list by any means and there are plenty of other waterfalls in the area that can be seen right from the car.  If you tackle all the ones listed below let me know and I'll add some more to the list.  Happy hunting!

Austin Creek Falls - Lake Whatcom Area (Whatcom) - This is a small waterfall but it's really easy to get to and only about 10 minutes from I-5.  This is a good opportunity to do a little wading in the creek as well.  During the summer the falls lose most of their oomph.

Big Fir Falls - Finney Creek Road (Skagit) - Kids tend to like a little bit of an adventure.  This little waterfall can be seen from the road but to get a good view means you have to climb down a little hill and then wade up the creek.  Like most smaller waterfalls, this one is not real impressive but very pretty and the kids can get right in the falls without risk to life and limb.

Bulson Creek Falls - Conway Area (Skagit) - This is a good one if your kids are a little more adventurous.   To get to the falls requires walking through mud and working around blackberry bushes.  It's not terribly difficult but is probably too much for most younger kids.

Clayton Beach Falls - Chuckanut Drive (Whatcom) - The trail to Clayton Beach is about a mile long and a pretty easy hike to one of the few sandy beaches in the area.  Consider the falls as a little side trip on the way to the beach.  The catch is to make sure there's some water going over.  After about June this one will be mostly dry unless there's been a day or two of rain.

Eagle Falls - Highway 2 (Snohomish) - Park and follow a short trail to a view of the Snohomish River tearing through a cool gorge.  There are plenty of cool rocks to look at and climb around on.   This makes a nice little rest stop on the way over Stevens Pass.

Explorer Falls - Monroe Area (Snohomish) - Getting to this falls involves a walk of about 1 1/3 miles up a dirt road.  There's nothing real tough about it but some very young children might need carried on the way back.  Once at the falls a little bit of scrambling around the creek is required to get a close view.

Feature Show Falls - Boulder River Area (Snohomish) - This waterfall is found about 1.25 miles along the Boulder River Trail.  The trail is fairly flat and travels through some excellent old growth timber.  It's a great all around hike at the falls at the end are one of the best in the area.

Forest Glen Falls - Cascade River Road (Skagit) - This waterfall makes a great stop about halfway up the Cascade River Road.  There are a ton of mossy rocks for the kids to climb on and around and the waterfall is one of the prettier ones around.

Gorge Creek Falls- Ross Lake Area (Whatcom) - Walk across the bridge and stare down at Gorge Creek below you.   The falls are impressive and the kids will probably appreciate getting out of the car to stretch their legs.  Add on nearby Ketchum Creek Falls as well.

Hard Scrabble Falls - Acme Area (Whatcom) - A short, fairly flat trail leads up the creek, through the woods to the base of the 85' tall bottom tier of the falls.  Come in the fall after a few days of rain and enjoy all the colorful colors of the trees and leaves.

Hilt Creek Falls - Rockport Area (Skagit) - Hilt Creek Falls can be seen from the road but it's a fun and easy climb down from the road to the edge of the canyon and a clear view of the lower two tiers.  If you're even more adventurous you can climb the rest of the way down to the base of the falls.  You may even be able to find a bootpath leading up above the bottom tiers to the pretty top section of the falls but this climb is a little steeper and more dangerous.

Ladder Creek Falls - Newhalem (Whatcom) - A trail leads over a suspension bridge across the Skagit River and over to the gardens on the opposite side.  The falls used to be lit up at night.   Sadly, the lights have been "under renovation" for several years and a gate blocks access to the upper sections of the falls.  Still a nice, short hike to a pretty waterfall.

Maple Falls - Mt. Baker Highway (Whatcom) - There are a few steep parts of this short trail but it shouldn't be an issue unless the ground is snowy or wet.  The falls are a series of short drops that are absolutely wonderful in autumn when the trees the creek were named after shed their leaves.

Nooksack Falls - Mt. Baker Highway (Whatcom) - Just a short walk from the road is the viewpoint for one of the more impressive waterfalls in the Baker area.  A fence protects viewers from a deadly fall but make sure the kids stay inside the fence.  There are also plenty of rocks to climb around on.

North Fork Falls - Mt. Loop Highway (Snohomish) - This is a short, easy trail to one of the most powerful waterfalls in NW Washington.  Add a stop at Lower Chocwich Falls to the trip for an easy 2-for-1 deal.

Prospector Falls - Bellingham Area (Whatcom) - Bellingham is blessed with a lot of these small, but pretty waterfalls right outside of town.  This one is located about a mile along a perfectly flat trail along Lake Whatcom.  This is another nice hike in autumn with a wide assortment of leaves covering the trail.

Soldier Boy Falls - Cascade River Road (Skagit) - Just before the end of the road, Soldier Boy Creek drops over this pretty waterfall.  There are plenty of other bigger falls around, but this is the only one that you can easily get close to.

St Louis Falls - Mt. Loop Highway (Snohomish) - This falls is a little tougher for some kids but if you've got slightly older kids (7 y.o. +) or kids that like a challenge this is a fun one.  The trail is around 1/5 of a mile long and climbs over a few logs along the way.  There's a creek crossing between two tiers of the falls that is fun and several entrances to the St. Louis Mine near the falls too.

Teepee Falls - Suiattle River Road (Snohomish) - The trail to this gorgeous falls is pretty steep but it's very short.  As long as your kids are 4 or older they should be alright.   The reward at the end is a pretty falls into a gorgeous blue-green pool at the bottom.  Several other waterfalls can be seen through the trees on the way to the falls too.

Webber Falls - Jackman Creek Road (Skagit) - Located up a logging road near Concrete, this waterfall is pretty impressive until about the middle of the summer.  Getting a clear view of the falls requires a short smash through the brush but if you're kids are into that kind of thing this is a fun one.

Wells Creek Falls - Mt. Baker Highway (Whatcom) - About 5 miles past Nooksack Falls you will find this nice waterfall on Wells Creek.  The falls can be seen from the road but a short trip up the creek will lead to a clear view.  Getting there usually requires crossing the creek twice which can be pretty tricky for kids younger than about 10 years old.   Even if you have young kids it's a nice drive with some really good views of Mt. Baker and it's only about 15 minutes from the highway to the creek.

Whatcom Falls - Bellingham Area (Whatcom) - There are a total of 5 waterfalls located in the park and all but one are fairly easy to view.  There are plenty of areas to wade around in the creek if the kids want to.  This is a great place for a picnic, a swim, a little time on the playground, and then peace and quiet on the drive home as the kids sleep in the back of the car.