I do not believe you went to the true summit, or are describing it. From your current descriptions of the route, location, and summit view, the information suggests otherwise.
The "highpoint" of McDonald Mountain (which is an unofficial name for this peak, by the way) is located at: 47.316779, -121.828702. In other words, near the center of the ridge... not near the northern end of the ridge as you indicate. You might want to check your topo map.
In addition, the highest point of McDonald Mountain is 3570' elevation, not 3310' elevation as you indicate. I think that (3310') is actually the elevation of the northern false summit. Yet another reason I question if your currently described route actually leads to the true summit, and if you even made it.
When going to the true summit of McDonald Mountain, it is much further with more cumulative elevation gain than what your page currently shows. When going to the true summit, the mileage is closer to 12 miles roundtrip and the cumulative elevation gain is closer to 3500' (including all ups and downs). This is clearly described on another page on SP.
This page still needs work, for material concerning the true summit and how to reach it.
An interesting side-note: McDonald Mountain is nicknamed "Big Mac" by some locals.
I agree with Redwic here. The 3570 pt is the highpoint. This is important because this mountain is a member of the 2k prominence club. The summit is best done by bike because it's a ways from the car.
It is obvious I hit the false summit. I will be back to finish what I started soon. I have updated the page with the correct information.
No problem. I slightly revised my vote. I know you'll do the appropriate changes and adjustments.
I have made the true summit and am in the process of fixing up this page.
After it was realized that the information for this mountain and its highpoint were incomplete, you were dedicated to finding time to go back, verify things yourself, and make the necessary adjustments to this page. Your diligence and persistence is something to be admired in this case, and I'm certain it does not go unnoticed.
For those who like visiting the locations of former fire lookout towers, http://www.firelookout.com/wamtrr.html, the old McDonald Lookout Site, http://www.firelookout.com/wa/mcdonaldmtn.html, is located just a bit further northwest along the ridge at Point 3280+.