The lazier way...
Great write up, LeeL. McDougal Rim is one of my favourite old-school trails in the valley.
That was a nasty route you took. The first time I was up there I did the same thing (probably following the same bad directions), but it was raining most of the time, and I eventually gave up and came back down the logging roads the way I had come. Very disappointing after climbing for what seemed like hours.
There is an "easier" way. First of all, drive up there to save the grief of a long road ride up a congested highway. Head west on Bartley Road from Hwy 97 between Westbank and the lake -- the road turns to gravel near the trailhead, and you should park at the cattleguard parking lot, which is where the singletrack descent spits out.
Gear up and continue (except on your bike now) west on the gravel logging road. You actually go downhill slightly at first, then flat/slight climb for maybe a kilometer or so with the creek on your left. Look for the first gravel road/trail going steeply up on your right and take it.
Most of this climb is rideable, but it's so steep and relentless that it will involve some pushing. Figure on spending close to an hour or so grunting up this beast (maybe less if you're in decent shape). It is worth it. Eventually you arrive at a T-junction with another logging road that goes to your right or left. If you're really tired or out of time, go right (description continues below -- skip one paragraph).
If you want to keep going uphill from the T-junction, go left for another half hour of climbing until you get to a small alpine lake. Look for singletrack descending to your right and take it down to the main lookout point (overlooking the city and the lake for miles -- you'll know it). That descent from the alpine lake to the lookout is awesome -- tight, rooty, rocky singletrack with some great faster sections.
Backing up a bit...if you reached the T-junction out of gas, go right instead of climbing left. Within a hundred metres or so, you'll see singetrack descending on your right. That's where you'll be going down, but don't dive in yet -- you'll want to see the lookout point first. Go straight ahead along the mostly flat logging road for maybe a half-mile or so, until the two-track dwindles into singletrack. Keep an eye out for the view opening up on your right -- a great spot for a picnic.
Once you've rested up at the lookout (no matter how you arrived there), head south on the flat two-track for a half-mile or so until you see the singletrack descending on the left. You'll hit a little bridge almost right away, and then a very short climb around a knoll...then it's all fast, swooping, rocky downhill singletrack right back to your car. It seems to go on forever.
...ebxtreme, I'd be happy to join you and your partner for this one when you guys are up here. Nothing hardcore about it (except the climb, I guess), no stunts, but it's classic mountain trail riding.
Getting lost to her doesn't have nearly the "adventure" appeal that it has to me....not to mention the fact that anything beyond 30 miles would get me in hot water....
