Tierra Redonda Mountain is a mountain in northwestern

San Luis Obispo County San Luis Obispo County (), officially the County of San Luis Obispo, is a county on the Central Coast of California. As of the 2020 census, the population was 282,424. The county seat is San Luis Obispo. Junípero Serra founded the Mission ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

. It is in the eastern portion of the Santa Lucia Range, separated from the main ridge by the Nacimiento River.

Location

The mountain is north of

Lake Nacimiento Lake Nacimiento is an long lake on the Nacimiento River in northern San Luis Obispo County, California. The lake contains many arms including Snake Creek and Dip Creek, nearer the dam, and the central Las Tablas and Franklin Creeks. Due to th ...

, with the summit being about a mile and a half (two kilometers) from the shoreline near the northwestern extremity of the lake. It is about 18 miles (30 km) from the Pacific Ocean at San Simeon. The elevation of the summit is 2051 feet (625 m). The primary maintained public road to the mountain is Interlake Road, San Luis Obispo County G14 (also signed in nearby Monterey County as G14), which passes about 1.5 miles (2.5 kilometers) northeast of the summit. This road intersects U.S. Highway 101 at Paso Robles, about 20 miles (32 kilometers) to the southeast. Oak Shores Drive winds around the western portion of the mountain from a junction with G14 to the shore of Lake Nacimiento, and Tierra Redonda Road comes around from the east. The mountain is part of a small island of

Bureau of Land Management The Bureau of Land Management (BLM) is an agency within the United States Department of the Interior responsible for administering federal lands. Headquartered in Washington DC, and with oversight over , it governs one eighth of the country's la ...

land, , entirely surrounded by private land. BLM has designated it as an Area of Critical Environmental Concern (ACEC), along with several other BLM holdings in the area (such as the

Carrizo Plain The Carrizo Plain ( Obispeño: ''tšɨłkukunɨtš'', "Place of the rabbits") is a large enclosed grassland plain, approximately long and up to across, in southeastern San Luis Obispo County, California, about northwest of Los Angeles. It con ...

and Cypress Mountain) due to the high concentration of unique, sensitive, and threatened species found in the vicinity, as well as for its singularly rich paleontological resources. This designation is in part because of encroaching development from the south, where private residences are being built on the shore of Lake Nacimiento, within the Oak Shores community. The region has also designated the region as open space in their General Plan.

Natural setting

Primary plant communities represented around the mountain include

chaparral Chaparral ( ) is a shrubland plant community and geographical feature found primarily in the U.S. state of California, in southern Oregon, and in the northern portion of the Baja California Peninsula in Mexico. It is shaped by a Mediterranean c ...

and blue oak woodlands, although grasslands and unusual sand dune formations also occur. Within the ACEC there are several sensitive plant species, some endemic to the area. These include several species of ''Chorizanthe'', among the most concentrated known anywhere, along with ribbonwood, Salinas Valley goldfields, San Luis Obispo County lupine, and the one-awned spineflower. While petroleum exploration is not presently occurring in the vicinity, the potential for oil and gas is considered by the BLM to be moderate. The Vaqueros Formation, which outcrops significantly on the mountain, accounting for its famous fossil beds, is an oil-bearing unit at the South Cuyama and

Russell Ranch Oil Field The Russell Ranch Oil Field is an oil and gas field in the Cuyama Valley of northern Santa Barbara and southern San Luis Obispo Counties, California, in the United States. Discovered in 1948, and reaching peak production in 1950, it has produced ...

s to the southeast, and the large, prolific

San Ardo Oil Field The San Ardo Oil Field is a large oil field in Monterey County, California, in the United States. It is in the Salinas Valley, about five miles (8 km) south of the small town of San Ardo, and about 20 miles (32 km) north of Paso Robles. ...

, one of the most active in California, is only ten miles to the northeast, along U.S. 101.

Historical Facts

The early pioneers of the area considered climbing to the summit of Tierra Redonda ("Terra Donda") a destination for a picnic. An American flag on a flagpole was visible from the lowlands. It was unknown who placed the flag or who replaced it when it became tattered.

References

{{Authority control Mountains of San Luis Obispo County, California Mountains of Southern California