Rio Dell is an unincorporated

Unincorporated area

In law, an unincorporated area is a region of land that is not a part of any municipality.To "incorporate" in this context means to form a municipal corporation, a city, town, or village with its own government. An unincorporated community is usually not subject to or taxed by a municipal government...

 community in Sonoma County

Sonoma County, California

Sonoma County, located on the northern coast of the U.S. state of California, is the largest and northernmost of the nine San Francisco Bay Area counties. Its population at the 2010 census was 483,878. Its largest city and county seat is Santa Rosa....

, California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

, United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. It is located on the south bank of the Russian River

Russian River (California)

The Russian River, a southward-flowing river, drains of Sonoma and Mendocino counties in Northern California. With an annual average discharge of approximately , it is the second largest river flowing through the nine county Greater San Francisco Bay Area with a mainstem 110 miles ...

 about 2 mi (3 km) north of Forestville

Forestville, California

Forestville is a census-designated place in Sonoma County, California, United States. The town came into existence during the late 1860s and was originally named Forrestville, after one its founders, but the spelling long ago became standardized with one "r". The population was 3,293 at the 2010...

. It adjoins Steelhead Beach Regional Park

Steelhead Beach Regional Park

Steelhead Beach Regional Park is a regional park on the Russian River north of Forestville, California, U.S.A. that is maintained by the Sonoma County Regional Parks Department. It covers an area of at on the north side of River Road...

, which provides a beach, picnic area, and a small craft launching area.

The main road is River Road, which passes northwest to southeast through Rio Dell. The next community to the northwest is Hollydale. The next community to the southeast is Mirabel Park.