Natural History Timeline
Natural History Timeline of the Boulder Valley
13000 BC9500 BC to 1850AD 500 BC
- World population: 100 million
- Coronado journeys up the Rio Grande to Colorado, releasing some of his horses to the wild.
- World population: half a billion.
- Invasive weed teasel introduced to North America.
- First reports of cheat grass in U.S. Cheat grass was probably introduced to both East and West Coasts directly from Europe.
- World population: one billion
- Otter and beaver trapping begins on the streams of the Rockies, ending beaver impoundments in riparian areas for decades.
- Bison are extinct east of the Mississippi.
- Boulder’s first reservoir, Pancost Lake, is constructed at the site of what is now Leggett-Owens reservoir.
- Bounty on wolves enacted in Colorado.
- Boulder flour mills, powered by ditches, grind wheat for locals and the East.
- 1091 bison remain in North America.
- First Arbor Day celebrated in Colorado. CU students and faculty transplant cottonwoods from Boulder Creek to around Old Main.
- Boulder’s last irrigation ditch begins construction.
- Ditches over-appropriate Boulder and South Boulder creeks.
- Boulder's reservoir building era begins.
- Reservoirs capture spring peak flows. Return flows to the Platte allow ditches to be developed farther east on the South Platte.
- Greenback trout become rare, due to sediment, toxic mine tailings, over-harvesting, agricultural diversions and interbreeding with non-native trout.
- Long-billed curlew populations begin sustained decline.
- Bounty enacted in Colorado ($1 for coyotes, $10 for cougars and bears).
- Last river otters reported of on South Platte.
- North American bullfrog introduced to Colorado, perhaps through fish stocking programs.
- Fox squirrel introduced to Colorado. Fox squirrels expand their range by following riparian corridors, invading urbanized areas, and inhabiting areas newly cultivated with deciduous trees.
- Tamarisk planted for erosion control on the Colorado and Rio Grande rivers.
- Bubonic plague enters the Western ecosystem from an outbreak in San Francisco.
- Last mink reported in Boulder Creek.
- Nationally, 5 million acres of forest burn and 78 people are killed in forest fires. Active suppression by U.S. Forest Service of all forest fires begins.
- Cheat grass infests entire West and considered the worst noxious weed.
- Goose populations plummet nation wide from habitat loss and over-hunting.
- World population: 2 billion.
- Last wolf in Colorado is killed.
- Plague reaches the Front Range of Colorado.
- Russian olive is distributed widely for wind breaks in the West.
- A remnant group of greenback trout is discovered in upper Boulder Creek watershed.
- PLAN-Boulder is organized.
- Less than 450 nesting pairs of bald eagles remain in the Continental U.S.
- 40 captured Canada geese are released in a Fort Collins lake and supplied with nesting boxes. These "live decoy" geese lure in migrating geese to Front Range lakes.
- World population: five billion.
- City of Boulder dedicates a portion of its senior ditch rights to in-stream flows in Boulder Creek through town.
- World population: six billion.
- West Nile virus enters U.S. near New York City.
- West Nile virus reaches Boulder and decimates corvid (crows, magpies, ravens etc.) and other bird populations.
- Bald eagles begin nesting along Boulder and St. Vrain creeks.
- About 380,000 bison live in North America.
- World population: 7 billion