The lower section of Eagle Creek is a favorite with Portland locals for its technical character and fun surfing. The rock is the same volcanic duff seen in the Sandy gorge and along the Bull Run.
Runnable flows usually occur when the Fish Creek gauge is between 300-1,500 cfs, and there has been recent local rain or low-elevation snowmelt. The correlation isn't always perfect, and also factoring personal preferences this gauge could be at 250 and Eagle Creek can still be runnable, or 2,000. Due to the imperfect correlation, there is a painted gauge on the take out bridge under Eagle Creek Rd, visible across the river from upstream of the bridge on river right. Two feet there is a healthy medium flow. Six inches is minimal and only the lower section below Eagle Fern is doable, 1 foot is low but fun, and 3 feet is high but still good, so long as you can avoid the wood.
Access for this run is within the vicinity of Eagle Fern County Park, which is a fee area. There are multiple pullouts where you can access the river both upstream and downstream from the park. The small dam that was formerly located in Eagle Fern park was removed in fall 2021.
On the Lower section the warmup whitewater is class II. There are some nice, easy surf waves adjacent to the park, these are accessible from the road and have been used as a park and play destination.
The Lower Falls with its fish ladder comes up within 10 minutes. Land on river right above the first concrete structure to scout or portage. The falls is more runnable with more water, generally down the right. The left looks frightening at most levels. The portage involves climbing up to an almost level carry or drag through the forest then descending one of several steep trails down to the river. It is recommended to scout your descent before taking your boat--some of them drop off precipitously at the end.
Below the falls the river steepens for ~1 mile, with long complex boulder gardens of the class III variety unless the water is high. Logs accumulate in this section so this writer suggests a trot down the easy trail to scout before launching. The trail to see Fish Ladder Falls (often portaged) is accessed from the pullout next to the yellow gate, and the Elbow section is downstream from there. At higher flows you will definitely want to scout Fish Ladder Falls to be sure you can hit the eddy above it, though it is more runnable at higher flows. The climax of this continuous section is a steep rapid at the apex of the right bend, sometimes called the Elbow. The road is a 5 minute walk through the forest from here. Downstream from the Elbow the whitewater remains continuous at medium and higher flows, and wood hazards remain abundant.
Below this section the run becomes less continuous but still amusing with many interesting class III rapids, excellent surf spots, and everpresent wood obstacles. The gradient eases further in the final mile.
The section below Eagle Creek Road to the Clackamas has been run but not in recent years due to huge log jams and a lack of whitewater. The presence of this wood accumulation just before the confluence with the Clack is verifiable by satellite view scouting.