This is a bushwhack, no established trail. Be confident with routefinding and/or GPS use. You will ascend tree-covered slopes to a ridge which you will then have to negotiate various obstacles on the ridge to open slopes on the south side of the summit mound.
See the Getting There section on the main page for directions to the trailhead.
East Ridge Bushwhack is the Red route in the photo above.
From your car (N44 degrees 54.416' W 122degrees00.959'), look south/southwest ahead at the obvious clearcut area from a few years ago. Climb up the right side of that clearcut. Try to avoid the clearcut as much as possible for three reasons: 1) the ground is steep and trampling on it erodes it easily and 2) it's covered with small trees that really need to grow and 3) it's covered in thorns and loose debris and going up the ridge on the right side of it is much easier.
Ascend the ridge on the right side keeping the creek on your right side within earshot to about GPS point N44degrees 54.326' W122degrees 01.164'. This will get you to the top of the ridge you can see from the car.
From that point, continue southwest to points (N44degrees 54.204' W122degrees 01.301') which gets you to where it steepens even more and then to (N44degrees 54.059' W122degrees 01.453") which is a flat spot (obvious on topo map) at 4200 feet with views of the summit. See this photo. From here you can see that you will continue up in a southwest direction until you gain the East Ridge.
So, continue in that direction on steep ground through trees and rhodies to point N44degrees 53.885' W122degrees 01.713' on the East Ridge. Turn right and follow the ridge. If needed I found it easiest to pass obstacles on the left (south) side. The first obstacle is a gendarme at point N44degrees53.884' W122degrees 01.886'. I passed just under the south edge of it on steep snow. Gain the ridge again and follow it as best you can. I found a little ways further east (N44degrees 53.881' W122degrees 02.057') was a small opening on the south side of the ridge with steep ground that I had to scramble over some rocks on the west side of a small snowfield. This can be bypassed easier about a hundred feet down then you need to climb again to regain the ridge. I am not sure how the ground is along the ridge itself.
After that point, continue on along the ridge or just below it west until you come to an opening in a small basin. In winter is was snowfields up to the right and also ahead diagonally slightly to the right. I am not sure if this is a rockfield, meadow, grassy area or what in Summer but you want to aim northwest and follow it up to the summit. The opening here is at N44degrees 53.863' W122degrees 02.322'. If it is too steep to ascend northwesterly, you can climb northerly to the trees and find eaier ground to traverse left (west) to the easier slopes to the summit. I figured the angle here at maybe 30 degrees when snowcovered. Once around (or through the trees) at the top of the field, you will see the open slopes up to the summit (north). See this photo for the lane at the top of the snowfield/open area to the summit (photo is from the summit looking down though). There is a cairn about 4 feet tall at the summit with a register inside to sign. Descend the same route.
Total mileage is 1.8 miles and elevation gain is about 2900 feet. (Think Dog Mountain in the Gorge but only half the distance so this is much steeper).
For Winter/Spring climbs, it is suggested to take crampons or snowshoes depending on conditions. An axe might not hurt either.
A GPS is recommended (or you could wand the route out).
There was a burn a couple years back which made it up and over the final ridge. Thus when you leave the rhodies and turn right on the final ridge it is pretty much completely clear of anything till the summit. Very easy but kinda ugly.