Rather than start at the Ira Springs trailhead, we parked on the north side of I-90 Exit 42 by the "shooting range". A nice boot path follows Mason Creek up the hill and intersects with the road about 0.2 miles from the trail head. We crossed the road and continued uphill. It's an easy hike until you're almost to the main trail then it is a bushwhack the last few hundred feet to the trail. You do get some good views of the creek cascading down the rocks. On the way down, we just stuck to the main trail, it didn't seem to take much longer even though it is much farther.
Google Maps link
Blue enjoyed wading in the lake.
Amazing, a picture where you can see Sly's eyes.
Little Mason Lake with Mt Defiance