Summary - If the gate is locked (and it probably is), this is a two mile logging road hike and summit hill bushwhack with modest elevation gain. On a clear day there are views from the north end of the summit. The bushwhack is relatively short with a few sections of thick brush. Round trip hike is under five miles with almost 1000 feet of elevation gain. Spotting with APRS or ATT cell service is possible. Bring HF gear as 2M contacts may be a chore. The hike and summit are on Hood River County Forest land with active logging sites. Don't block gates and pull over for logging equipment coming your way.
Long Version - Middle Mountain, about thirty minutes south of Hood River Oregon, is a rather nondescript hike and bushwhack that does, on clear days, have nice views to Mount Adams. From Hood River take highway 281 to Summit Drive to Gilhouley Road. Middle Mountain sits on Hood River County Forest land, which is actively logged, and there is a gate on Gilhouley Road at (45.61303, -121.58456) that you are likely to find locked. Gilhouley is very narrow and the last two miles to the gate are not paved but it is Prius-ready. There are two small turnouts right before the gate; be sure you are off the road and not blocking the gate.
From the gate, you will hike along a well-graded logging road past a couple of active logging sites. When you hit the two mile-ish mark (45.59024, -121.59500) look for an abandoned forest road going up in the general direction of the summit. This path more or less peters out though most maps show it going to the top. When it disappears, point yourself uphill. Some zigging and zagging to avoid the bigger brush patches in your path will bring you to the summit.
The summit is treed but there are nice views of the valley and Mount Adams on the north end. You will find lots of places to toss a wire but not much protection from the wind. I recommend bringing HF gear as 2M contacts on the hills between Mount Defiance and Mount Hood are usually tough to get. Spotting is generally easy as there is good cell (ATT) and APRS coverage here.
So... an easy approach, a modest bushwhack, nice views, and back to Hood River in time for lunch. Not a bad way to spend a morning even if it is a one-pointer.