Many rivers in that area are "fly fishing only"; to protect both the streams from destruction-and the species that inhabit them from decimation.
You'll find protected Bull Trout, in the Metolius. But, protected means catch n' release ONLY. It is illegal, to harvest them--as they are on the endangered species list. You'll find Bulls up to 20 pounds, in this revered river. Look for them beneath bank cover, and around submerged structure, and in deep pockets associated with bridges.
For summer steelies; the Deschutes is the go-to river. However, the summer run fish don't begin to stage at the mouth (i.e. at the Columbia River), until mid-July. So, it's likely going to be too early to find any summers upstream. On the other hand; it is an excellent rainbow and brown trout fishery.
Good luck; and be sure to double check the reg's before setting out.