Passage: Strong high-altitude wind carried much of this material east-northeasterly from the volcano at an average speed of about 60 miles per hour (100 km/h). By 9:45 a.m. it had reached Yakima, Washington, 90 miles (140 km) away, and by 11:45 a.m. it was over Spokane, Washington. A total of four to five inches (100 to 130 mm) of ash fell on Yakima, and areas as far east as Spokane were plunged into darkness by noon where visibility was reduced to 10 feet (3 m) and 0.5 inches (13 mm) of ash fell. Continuing eastward, St. Helens' ash fell in the western part of Yellowstone National Park by 10:15 p.m. and was seen on the ground in Denver, Colorado, the next day. In time, ash fall from this eruption was reported as far away as Minnesota and Oklahoma, and some of the ash drifted around the globe within about two weeks.

Question: At what time did the volcano ash reach Spokane?
11:45 a.m