Secret Town, California

Gold Run was a former mining town of the California Gold Rush, located in Placer County, California.The former settlement is a listed California Historical Landmark (#405).

Little York (previously: Little New York) is the name of one of the first gold mining towns established in Nevada County, California as well as the name of the township in which it was situated. The town was located on the Lowell Ridge between Steephollow Creek and the Bear River, about 13 miles east of Nevada City, California and about 1 mile southwest of Dutch Flat, California at an elevation of about 2800 feet.

Walloupa (also, Waloupa) was a historic mining community in Nevada County, located about 1/2 mile south of You Bet. It was named by its white developers after a Nisenan chief, and should not be confused with the Nisenan village of Walloupa, which was located about 15 miles to the west near Rough and Ready.

Iowa Hill (formerly, Iowa City) is an unincorporated community in Placer County, California, United States. The town is located 6.5 miles northwest of Foresthill 9 miles east of Colfax and 58 miles northeast of Sacramento. It lies at an elevation of 2861 feet. The community relies completely upon solar panels and generators for power. Its population is around 200 people. Iowa Hill Road claims a small handful of lives every decade, and along with the community's "off grid" status, prevents the town from growing in population. The community boasts many hardcore cyclists and is appealing to visitors due to the abundance of recreational opportunities. Iowa Hill Road is a very steep, one-lane, winding road embedded within the mountains. There are no safety guardrails. Since ambulance service from Colfax takes a long time, emergency medical transport is supplemented by CALSTAR, the area's air rescue helicopter. A landing pad is located next to the town fire house.

You Bet is a small unincorporated community in Nevada County, California. You Bet is located in the Sierra Nevada foothills, 7 miles (11.3 km) east of Grass Valley and 5.5 miles (8.9 km) northeast of Chicago Park.

Dutch Flat (also, Dutchman's Flat, Dutch Charlie's Flat, and Charley's Flat) is a small unincorporated community and census-designated place (CDP) in Placer County, California, United States, about 30 miles (48 km) northeast of Auburn along Interstate 80. It was founded by German immigrants in 1851 and was once one of the richest gold mining locations in California. Dutch Flat is now registered as a California Historical Landmark.The community's ZIP code is 95714 and its area code 530.

Red Dog (also known as Brooklyn or Brooklin) was a California gold rush mining town located in the Gold Country in south-central Nevada County, California, United States, 6 mi (9.7 km) northeast of Chicago Park. Red Dog Hill, a mine and campsite, was founded by three men all under the age of 22, and was named by their youngest, a 15-year-old prospector. As mining operations grew, the campsite became a settlement, and then a town with a population of 2,000 residents, before it was eventually abandoned. Still considered important today, Red Dog Townsite is listed on the National Register of Historic Places.

Long Ravine Trestle is a pair of deck plate girder railway bridges near Colfax, California. They carry the Union Pacific Railroad Roseville Subdivision over Long Ravine and Interstate 80, traversing the Sierra Nevada. The original crossing was a three-span Howe truss bridge with wooden trestle approaches, constructed as part of the first transcontinental railroad. The Nevada County Narrow Gauge Railroad was subsequently constructed under the bridge between 1875 and 1876. The trestle portions of the bridge were replaced with embankments by this time. The original wooden trestle was replaced with an iron structure in 1890. Southern Pacific double tracked the line and constructed the two modern bridges, completed in 1912 and 1913, to carry the rails. The southern span was retrofitted in the late 1958 to allow for the new U.S. Route 40 freeway to be routed underneath. The bridge is predominantly used for freight trains, but is utilized by the daily Amtrak California Zephyr.

Rollins Dam (National ID # CA00255) is a dam on the border of Nevada and Placer counties in northern California, in the United States. The earthen dam was constructed in 1965 by the Nevada Irrigation District, with a height of 228 feet (69 m), and a length of 1,840 feet (560 m) at its crest. It impounds the Bear River, a tributary of the Feather River, for hydropower, flood control, irrigation water storage, and municipal water use. The dam is one of the ten facilities owned and operated by the Nevada Irrigation District. The dam is part of the Yuba-Bear Hydroelectric Project. The reservoir it creates, Rollins Reservoir, has a normal water surface of 1.3 square miles (3.4 km2), and a maximum capacity of 66,000 acre-feet. Recreation includes trout fishing in the spring, and bass fishing in the summer. The California Office Of Environmental Health Hazard Assessment has issued a safe eating advisory for any fish caught in Rollins Reservoir due to elevated levels of mercury.

The Bear River Bridge was located in Nevada County, California, from 1908 to 1963, replacing an earlier wooden structure. When built over the Bear River, it was the highest railway bridge in the state. The bridge was built by the Nevada County Narrow Gauge Railroad, under the management of Sarah Kidder. From the surface of the water, at an average stage, up to the track was 200 feet (61 m). The total length was about 900 feet (270 m), and at the time of construction there were no approaches, the opposite banks being abrupt. The pier foundations were built of reinforced concrete, requiring more than 500 cubic yards. The piers and superstructure were of structural steel, of which about 500 tons were used. All the steel material was furnished by the American Bridge Company of San Francisco, and the constructing contractors were Shattuck & Edinger Construction Company, also of San Francisco. The total cost of the bridge was approximately US$70,000. The engineering involved much difficulty—principally due to the unusual height of the structure. At the beginning of the work the contractors stretched a 2.25 inch diameter steel cable from bank to bank more than 200 feet (61 m) above the Bear River, and 1,000 feet (300 m) long. By means of this cable all of the structural steel material required, as well as the concrete, were hoisted and conveyed by a trolley to the required point and lowered to the proper position. It took about six months to complete construction. Only a small force of men were employed and the work necessarily progressed rather slowly. The bridge was on a 1 mile (1.6 km) long cut-off which shortens the road 2 miles (3.2 km), and also eliminated two long wooden bridges, each 100 feet (30 m) high, and one 400 feet (120 m) tunnel. The bridge was taken down to make way for the Rollins Dam in 1963.

Sugar Pine Dam is an earthfill embankment dam in Placer County, California, approximately 7 miles (11 km) north of Foresthill. It impounds North Shirttail Creek, a tributary of the North Fork American River, and serves as the primary municipal water supply for the Foresthill community.

Shady Glen is an unincorporated community in Placer County, California. Shady Glen is located 1.25 miles (2.0 km) north of Colfax. It lies at an elevation of 2451 feet (747 m).