Black Diamond Mines Regional Preserve
Photo MARELBU · CC BY 3.0

Black Diamond Mines Regional Preserve

Antioch, Contra Costa County, CA

Parking$5 per vehicle
Source
DogsLeash in developed areas
Source
Hours8 a.m.; closing 5–8 p.m. by season
Source
Black Diamond Mines Regional Preserve
Photo MARELBU · CC BY 3.0
Size
4,646 acres Source
Managed by
East Bay Regional Park District

About Black Diamond Mines Regional Preserve

Former coal mining country near Antioch with mining history and hilly trails. Source

The East Bay Regional Park District began acquiring land for Black Diamond Mines Regional Preserve in the early 1970s. Today, most of the mining district is within the Preserve's nearly 8,533 acres. The area is an ideal location for hiking, picnicking and nature study. Naturalists conduct a variety of programs relating the Preserve's natural and historic resources. For information phone (510) 544-2750 .
From the official park page · checked Oct 15, 2026

Facilities

  • Camping
  • Drinking Water
  • Historic Site
  • Picnic Area
  • Restrooms

Facility details: OpenStreetMap

Black Diamond Mines Regional Preserve at a glance

PPPWCWCWCWCWWi
  • PParking · 3
  • WCRestrooms · 4
  • WDrinking water · 2
  • iVisitor center · 1: Sidney Flat Visitor Center
  • Named trails · 12

Outline: CPAD. Points and trail lines: OpenStreetMap contributors. Not for navigation.

Trails

TrailMapped lengthElevationSurface & uses
Stewartville Trail4.1 mi1,343 ft up & down292–1,140 ftUnpavedBikesHorses
Black Diamond Trail3 mi1,345 ft up & down751–1,609 ftUnpavedBikesHorses
Old Homestead Loop Trail3 mi1,321 ft up & down274–898 ftUnpavedBikesHorses
Lougher Loop Trail3 mi1,772 ft up & down437–1,226 ftUnpavedBikesHorses
Ridge Trail2.8 mi1,237 ft up & down551–1,274 ftUnpavedBikesHorsesNo bikesNo horses
Star Mine Trail2.7 mi822 ft up & down392–847 ftUnpavedBikesHorsesNo bikesNo horses
River View Trail2.5 mi1,300 ft up & down259–1,049 ftUnpavedBikesHorses
Contra Loma Trail1.3 mi594 ft up & down300–914 ftUnpavedBikesHorses
Nortonville Trail1.2 mi725 ft up & down738–1,114 ft
Upper Oil Canyon Trail1.2 mi672 ft up & down501–1,187 ftUnpavedBikesHorses
Carbondale Trail1.1 mi415 ft up & down910–1,192 ftUnpavedBikesHorses
Loop Trail1.1 mi613 ft up & down249–822 ftUnpavedBikesHorses

Trail names and mapped lengths come from OpenStreetMap; lengths count only the part inside the park boundary. Up-and-down totals (climbing plus descent, one way) and elevation ranges are estimates from USGS 3DEP elevation (about 15 m grid) sampled along the mapped line. Use the official guide map for the route and current closures.

Rules & reservations

Official park page
  • Dogs

    Dogs must be leashed in parking lots, picnic areas, lawns, and other developed areas, and may be off leash under control in undeveloped open space (district rules). Source

Gate hours change through the year; check the posted schedule. Greathouse Visitor Center: Fridays 10 a.m.–2 p.m., weekends 10 a.m.–4 p.m.

Map & directions

5175 Somersville Road, Antioch, CA 94509

1Location overview · map data © OpenStreetMap

37.957671, -121.856083Get directions

Nearby parks

Straight-line distance

Sources & verification

Last verified: Oct 15, 2026
  1. California Protected Areas Database (CPAD) 2026aname, county, agency, access, acres
  2. East Bay Regional Park District dog rulesdogs
  3. East Bay Regional Park District park pageofficial_url, hours, address, description, fees
  4. OpenStreetMap facilities and trailsfacilities.camping, facilities.drinking-water, facilities.historic-site, facilities.picnic-area, facilities.restrooms, trails
  5. U.S. Census Bureau place boundaries (nearest place)city
  6. OpenStreetMap: parking, restrooms, water, trailheads, trail lines, and bus stopsvisit
  7. Terrain Tiles elevation (USGS 3DEP), sampled every 20 m along OpenStreetMap trail linestrails.elevation
  8. Official park page (introduction excerpt)intro
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Black Diamond Mines Regional Preserve · Photo MARELBU · CC BY 3.0