The park, named for the creek flowing through the property, contains the historic stone John Marsh house, ranching buildings, and numerous pre-historic archaeological sites.

It represents the Mexican period in California history, was an important site for the Miwok and other Native American people, was home of vaqueros, was the end point of the California Trail (with the first party over the Sierra Nevada coming directly to the John Marsh rancho at his invitation), and its archaeological site has produced artifacts going back 7,000 years.

[4][5][6][7] The house has been publicly owned as a historic site since 1960, when the owner Henry Cowell donated it to Contra Costa County for preservation and restoration.

[9] Archaeologists have found that Native Americans lived in the East Contra Costa County area at least 7,000 years ago.

These findings are important because they shed light on a rare and unique manifestation of a pre-historic culture in California seldom seen in the archaeological record.

[10][11][12][13] Marsh, a widower, was a native of Massachusetts, who had previously lived in Minnesota, Illinois, Wisconsin, Missouri and New Mexico before settling in Los Angeles, California.

[15] A highlight of the park is the home of John Marsh, which was begun in 1853 and completed in 1856, and which has been undergoing extensive renovation for several years.

Initially, Marsh lived in a four-room adobe house which had been built on the property for him by local Miwok Indians.

[16] After he married Abby[a] Tuck in 1851, he retained San Francisco architect Thomas Boyd to design a grand new mansion.

The new Gothic Revival style house was three stories high and had an observation tower that rose 65 feet (20 m) into the air.

[16] Images from the Historical American Building Survey (HABS) collection in the Library of Congress shown here depict the differences in the two structures.

The house has an exterior wall covered with twelve-inch (300 mm) wide, buff-colored sandstone blocks.

Inside the stone exterior, there was a four-inch (100 mm) void, then another wall built of adobe brick.

[c] The architect chose to use an asymmetric Victorian floor plan, instead of the symmetrical Georgian style that was popular in most of the larger California houses built in the 1850s.

[21] The original tower was built entirely of stone and designed for defense against unwelcome visitors, because the area was considered "bandit country," with no organized law enforcement agency at the time.

During the 2006 reconstruction, inspections showed the roof so damaged and leaky from rot that was given a temporary cover of tin, as shown in the 2012 photo above.

[24] The John Marsh House was listed on the National Register of Historic Places (NRHP) with Reference Number on October 7, 1971.

[25] Among the major objectives for future restoration and reconstruction work are:[25] As of 2013, nearly one million dollars had been spent on stabilizing the house since 2006.

[27] Creation of a visitor center, trailheads, picnic areas, parking, equestrian facilities, campsites and accommodations for special events, such as a farmers market, are all under consideration for future development.

Larry Myers, a representative of the California Native American Heritage Commission, urged state park officials to keep the burial sites off-limits to the public.