First Nations people had led a nomadic existence in the Okotoks area for thousands of years prior to the arrival of the Europeans. The First Nations left us with a legacy in the name of Okotoks, which is derived from the Blackfoot word "Okatok", which means "rock". Plains First Nations, like the Blackfoot, did not use rivers as a means of transportation, instead they were often an impediment to travel and a good river crossingwas important. There were safe river crossings at the present day Town of Okotoks. The Blackfoot may have referred to this area as "Okatok" because of the Big Rock which they used as a reference marker in their journeys. The Sarcee called this area "chachosika" meaning valley of the big rock. The Stoney name is "ipabitunga-ingay" meaning "where the big rock is".
Among the earliest European settlers in Okotoks were Kenneth Cameron and Alexander McRae, who settled on the banks of Sheep Creek after their oxen drifted away in a snowstorm in 1882. Cameron established a stopping house on the north side of Sheep Creek, uphill from where the Macleod Trail crossed river. Cameron Crossing, as it became known, is believed to be near the present-day walking bridge south of the library. There was a second river crossing which existed prior to Cameron's arrival. It was named after John Macmillan who ran a stopping house near the present-day railway bridge. The Macmillan stopping house also housed the Okotoks post office until 1884.
The Macleod Trail was a significant north-south transportation line. It was the only wagon trail linking Fort Edmonton, Fort Calgary, Fort Macleod and destinations in the United States. While it was later replaced with a rail line, it set the pattern for the transportation corridors we see today. In 1887, prior to the railroad's arrival in Okotoks, there were approximately 20 houses in the frontier town. The C & E rail line between Fort Calgary and Fort Macleod was completed in 1892-3 and the Okotoks train station was built in 1892. The arrival of the railway and Lineham's lumber mill were key factors in the area's early growth. In 1892 John Lineham brought his first run of logs down Sheep Creek to his mill in Okotoks. The mill employed as many as 100 men and was one of the biggest industries in the region.
From approximately 1892 to1896 the fledgling community was called Dewdney, after the Lieutenant Governor of the North West Territories. However, it was changed back to Okotoks because there was another Dewdney in the North West Territories. Okotoks officially became a town on June 1, 1904.
In 1906 Okotoks enjoyed telephone service and electric lights. Natural gas arrived in 1912, but it wouldn't be until 1952 that residents were able to enjoy a public water works and sewer system. Like many small prairie towns, fires and floods plagued Okotoks in the early years. The Sheep River flooded its banks in 1902, 1915, 1940, and 1963, among others. Many of the town's early buildings were lost to fire. Whole blocks burned at times. When oil was discovered in Turner Valley in 1914, Okotoks quickly became a regional oil distribution centre. It earned the title "Heart of the Oilfields" because equipment stopped on the rail line in Okotoks before completing its road journey to Turner Valley.
For the most part, Okotoks remained unchanged through the first half of the century, with the population settling around 600 people. Wooden sidewalks and hitching posts were removed in the late 1920's; men left to fight in the first and second world wars, and residents endured the Depression. The economic upturn came in the late 1970s. The population doubled to 1,928 people in 1976. With the increase came a need for larger town facilities. The town expanded into a bigger town hall in 1974, it opened the Recreation Centre in 1982, a new high school in 1985, the library in 1991, and a new fire hall in 1992.
In 2004, the Town of Okotoks celebrated its 100th
anniversary. That year, Okotoks was home to 12,187 residents. The most recent census, conducted in May 2012, shows the population has again almost doubled to 24,962.