The gravel road to trailhead is in very good condition, no problem for passenger vehicles. We accidently separated a doe and fawn on the ride up, and had to stop the car to let them get back together (we were inadvertently driving the fawn -- very slowly -- up the road with the doe behind us). There is a decent pit toilet at the trailhead, and plenty of parking.
We arrived about 0915; two vehicles were already in the parking lot. Clouds obscured the summit and most surrounding views, and mist rose continuously up the slope from the very wet vegetation, which was dripping with an immense amount of dew. Two hikers descended while we were still in the parking lot, both sopping wet from the knees down. The temperature was in the 50s and rather cooler than we had expected.
The ascent via the many switchbacks that scale the very steep talus slope was wet as well as quite misty and foggy. Plants laden with moisture bent over the trail drenching clothing and skin when brushed. Within minutes there were no views possible at all with the trail vanishing a few steps ahead. The narrow route is in good condition however, and the wildflowers were riotous in their color and variety -- a stupendous display.
After more than an hour in the fog we reached the first saddle and crossed from the west to the east side of the mountain. At the this point we encountered the only other group on the mountain so early, already descending. Views to the west, north, and south were still completely obscured, but we got glimpses of various mountains and the Sauk and Skagit Rivers below through the still-rising mist. Around 1100 the mist began to shift rapidly, offering quick peek-a-boo views from the NE to the SW. We moved on to the nearby saddle where by 1130 or so virtually all clouds and mist disappeared. Suddenly we were surrounded by 360 degree views including Mt. Baker, Sisters, Glacier, San Juan Islands, and much more. Sauk Lake below was a wonderful green/blue color and ice-free. There are snow fields at the saddle running fairly continuously to the summit.
On the descent the spectacular views and astonishing wild flowers continued. By this time (noonish) the temperature was probably in the low 70s and we were encountering ascending groups every few minutes. When we reached the parking lot at about 1300 we found 16 vehicles arrayed there! And more arrived as we were packing gear for our departure.
Insects were not an issue at any point. In addition to the deer we saw numerous birds, picas, chipmunks, and a field mouse (?). The trails was essentially mud-free, and the few heavily eroded sections appeared to had been repaired at some point. The descent through clear skies was spectacular, but somewhat disconcerting given the narrow path bordered by an extraordinarily steep talus slope. The view upward from the parking lot (unavailable to us earlier due to fog) was beautiful, but potentially daunting for those about to set out -- it appears both high and steep.