North Table Mountain is a mesa on the eastern flank of the Front Range of the Rocky Mountains. The 6,555-foot mesa summit is located in North Table Mountain Park, 3.4 miles north east of downtown Golden, Colorado, in Jefferson County.
The most distinctive feature of the mesa is its nearly flat cap that was formed by ancient Paleocene lava flows. The lava flows originated from the Ralston dike, about 4 miles to the north and were once continuous from North to South Table Mountain. The two mesas are now separated by Clear Creek which has cut a channel between them.
North Table Mountain is a popular scenic and recreational destination and it is preserved as public open space by Jefferson County and the Access Fund. Recent and ongoing projects by Jefferson County Open Space have resulted in the construction of several new trails and eliminated large numbers of unofficial trails.
136 acres on the southwest slopes is open space owned by the City of Golden. This includes the North Table Mountain Trail which is 1.5 miles and traverses the southwest side of North Table Mountain below the cliff band. There are excellent views of the Golden Valley from this trail which is moderate to advanced in difficulty, with 300 feet elevation gain from the north and 400 feet elevation gain from the south. The hiker can continue southeast on Peery Parkway to the parking lots for the Golden Cliffs trail.
North Table Mountain is underlain by sedimentary rocks of the Denver Formation, which spans the interval from latest Cretaceous to early Paleocene time. An exposure of the Cretaceous-Tertiary (K/T) boundary layer has been identified and documented on nearby South Table Mountain.
Three prominent, columnar jointed, cliff-forming lava flows can be seen on North Table Mountain, one exposed part way up the northwest slope, and two that form its cap. The Ralston Dike, a body of intrusive monzonite located about 2 miles to the northwest, probably represents the volcanic vent from which the flows erupted. The flows are about 62 to 64 million years old according to radiometric dating, which places them in the early Paleocene epoch. Generally referred to as basaltic, they are classified either as monzonite (the lowest flow) and latite (the upper two flows), or as shoshonite. They contain the minerals augite, plagioclase, and olivine altered to serpentine, with accessory sanidine, orthoclase, apatite, magnetite, and biotite.
Vegetation and Wildlife
Among the animals known to frequent the mesa through time, according to local newspaper accounts, are mountain sheep, coyotes, mountain lions, deer, elk, rattlesnakes, and more. Of these, most except for the mountain sheep continue to live upon the mountain today. North Table Mountain is listed as an official "eBird Hotspot" (https://ebird.org/hotspot/L2381632) with 108 species identified. eBird is managed by the Cornell Lab of Ornithology and is the world’s largest biodiversity-related citizen science project, with more than 100 million bird sightings contributed each year by eBird contributors around the world. Several areas are closed seasonally to protect several species of nesting raptors. In the late 19th century bees also nested in the cliffs.
Vegetation is mostly Foothills Shrublands with some prairie and riparian plants. Many varieties of wildflowers bloom throughout the Spring, Summer and Fall.
The top and the slopes of North Table Mountain, including the southwest slope owned by the City of Golden, have been substantially disturbed by ranching and mining. Much of the historic agricultural use was on top of the mesa. Disturbance on the southwest slope included a tramway to bring quarried basalt rock down from the top of the mesa. There is evidence that springs on the slope have been improved to increase the delivery of water. Numerous roads were built on the slopes of the mesa.
Regardless of the disturbance, the mesa has a diversity of habitats. The relatively flat top of the mesa is mostly prairie with a few wetlands that are both natural and man-made. The slopes are mostly foothills shrubland, with a few small riparian zones. Specifically, the southwest slope has thickets of American Plum (Prunus americana) that bloom in early April before the leaves emerge, turning the view from town white. In mid-spring one might catch a sweet whiff of Mountain Ninebark (Physocarpus monogynus) that is found nestled down in the riparian zones. The City of Golden North Table Mountain trail is an excellent place to look for spring wildflowers, both annuals like Scrambled Eggs (Corydalis aurea) and perennials like Foothills Penstemon (Penstemon virens). Finally, there are grasses throughout the spring and summer, from the early June Grass (Koeleria macrantha) to the summer and early fall Big Blue Stem (Andropogon gerardii).
Content provided by Tom Schweich and Wikipedia
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