Spokane Timeline 

(All dates are correct to the best of my knowledge, but obviously are subject to error)

4 billion years ago, Earth formed.
80-35 million years ago, Cascade Mts formed, Olympic Mts are islands out to sea.
34 million years ago, creation of Columbia Plateau,
34-10 million years ago, Floods of lava cover Columbia Basin, destroying Columbia River waterway.
40,000 years ago, First ash deposits from Mt St Helens.
10 - 20 thousand years ago, Washington Ice Age.
10,000 years ago, Kennewick man remains (first indians?)
1700, horses introduced to indians on Columbia plateau, buffalo now gone from plateau.
1741,  Russian Explorers trade for sea otter pelts in Alaska area.
1774,  Juan Perez sights Olympic Mts.
1778,  James Cook explores Coast of Washington/Canada.
1792,  Robert Gray names Columbia River after his ship.
1807,  David Thompson charts Columbia River
1810,  Spokane House fur trading, Chief Garry's father frequented the place.
1816,  Advent of photography
1817,  approx.,  next to last Mt St Helens eruption dropping ash and darkening the day in Spokane.
1825,  Forts Vancouver and Colville built on Columbia River.
1846,  49th parallel set as boundary between Canada/USA
1853,  Washington Territory created
1856,  Fort Simcoe established
1857,  Rise of Spokane Garry as notable chief
1859,  Mullan road from Walla Walla to Fort Benton
1860,  Okanogan gold/silver discovery
1873,  Glover, the Father of Spokane
1873,  Oldest still standing house in Spokane,1883, 2424 W 2nd
1885,  First powerplant on river.
1886,  First brick house on north side of Spokane River,1886, 1843 W Broadway
1886,  Rich Mine development causes development of Spokane from shacks to brick bldgs 
1888,  Residences begin to be electrified.
1889,  Washington territory becomes the 42nd state, Spokane's Great Fire
1890,  Spokane's age of elegance due to mining riches flowing here
1902,  Motorcycles in general usage.
1909,  Model T in usage.
1974,  Worlds Fair: theme is the environment, Spokane's environment takes turn for the better
1980,  Last Mt St Helens eruption dropping ash and darkening the daylight in Spokane