This hike to the west side of Grass Mountain is described in Footsore 1, pp. 226-228. Here's what they say about the view from the top (at 4382 feet):

"What a world! Out the White River to Enumclaw, Puget Sound, Seattle, the Olympics, Across the Forbidden Valley of the Green River to McDonald, Issaquah Alps, Si, Baker, Glacier, and beyond the Cascade Crest to Stuart. Let's see, there must be something else. Oh yes, The Mountain. Pow.... [but] The summit is decorated by the usual batch of overcommunication towers."

This hike off 410 west of Greenwater is just an old logging roads hike -- no trails, and clearcuts all round. But it's accessible year-round, and there is virtually no one else out there. Also, there are great views of Mt. Rainier and surrounds all along the hike, and at the top you can see virtually 360 degrees, including North Cascades and downtown Seattle. The gate at the bottom keeps out vehicles, although there may be access through other points (but I haven't seen any vehicles and some spots are too washed out for them).

Heading east on Highway 410 from Enumclaw, pass the Mud Mountain Dam cutoff. Go about 6 miles past there to where 410 curves noticeably to the right (SE)(grid E9 in Green Trails map Enumclaw, WA -- No 237). (You can tell you are approaching the correct gate because the one just before it also has parking on the right (S) side of the highway; that gate is called the Bridge Camp Gate.) The next gate on the left (N), the one for this hike, has power transformers at the start of the logging road.

It would be better to have a more detailed map, but you can do this with a GreenTrails map. Be sure to keep track of where you are with your compass and map so you don't get pulled off on the wrong sideroads, because most of them deadend. Basics, with extremely rough mileage, are this: North, then 1 mile east, 0.5 miles north, 0.5 miles west, o.5 miles east, a long wiggly stretch west (2+ miles), two right turns at Ts (NOT at spurs) that send you north and west over a mile, and then a sharp left (W) to head up to the peak/communications structures (0.5 miles). If I'm reading Manning correctly, one-way mileage is 8.5 miles, so you can see my estimates above are on the low side.

Photos were taken a few weeks before but conditions were the same. I didn't bring camera on February 22 so didn't get the shots from the top, which are more dramatic.