Multnomah Falls is one of the great treasures of the Columbia River Gorge in northern Oregon along the Columbia River.  The waterfalls along this section of I-84 are spectacular and should be visited by anyone touring this section of the state of Oregon.  That being said, easiest access to the waterfalls is done on the Historic Highway which is quite narrow and winds along steep cliffs for several miles, which may not be the right road for RVers pulling or driving a large rig.

If you want to pull up in your RV and walk up a few hundred yards to one of the most spectacular waterfalls in the Gorge - Multnomah Falls is a great choice.  The exit is a left exit off the freeway into a large parking lot.  Near the east side of the parking lot there are several large pull in RV parking sites with easy on and off freeway access.  

From the parking lot there is a paved path under the freeway to the Multnomah Falls Lodge where food and beverages are served.  There are paved paths to several lookouts of the Falls, depending on your available time and fitness level.

The trailhead also goes above Multnomah Falls to see the creek/river that feeds the Falls and continues into the trail system that goes throughout the Columbia River Gorge, including Larch Mountain directly south of the Falls.  

While the parking lot is labeled for day use only, if you have to make an emergency overnight stop, it is common to find RVs parked overnight in the parking lot and the day use rule does not seem to be actively enforced.  Note that there is a freeway on both sides of the parking lot, as well as active train tracks, so the road and train noise is significant, day or night.  It might not be a great night sleep, and there are no amenities, but if you are tired or have an emergency stop need, the parking lot at Multnomah Falls is an option with space to park your rig until daylight.