Used the south parking lot (Pinnacle Peak Park). Arrived about 1:30pm and there were plenty of spaces.
Did a lollipop hike (detailed below). Covered 3.2 miles in 2:15 (1:05 to ascend, 0:30 at the top, then 0:40 to descend).
On the way up, followed the road all the way to its end, then took the trail through the trees anti-clockwise. The last ~200yds before the summit had some very steep and rocky sections, though exposed roots and trees made for some good handholds. Climbed to the top of the fire lookout, which has some good views, though much is obscured by trees. Mt. Rainier was better viewed from the road on the way up than it was from the tower.
On the way down took the north exit from the summit, which proved to be a much gentler and wider track than the ascent. The basalt columns were clearly visible this route, and were most prominent at the 1700ft mark right by the switchback, but also a little higher up at about the 1730ft mark. Staying on the wide track (i.e. avoiding the turn for the Cal Magnusson Trail), we had to duck under some large fallen trees. Then keeping to the right we rejoined the road again part way down.
Overall the trail was in very good condition, and the fallen trees could be avoided by rejoining the road earlier. The information posted on the poles along the road were interesting to read, and we even stumbled upon a couple of black-tailed deer in the clearing near the top.