Porphyry, California

The same ground, surveyed 82 years apart. Drag the handle to wipe between them. Both sheets are United States Geological Survey originals; neither has been altered.

1901 1983

Matched by testing this settlement's coordinate against the published boundary of every sheet in the United States Geological Survey's historical collection. Each opens the scanned sheet at the Survey.

• 1901 USGS Southern California Sheet No. 1 quadrangle1:250000, 6 printings
• 1902 USGS Corona quadrangle1:125000, 7 printings
• 1904 USGS Southern California Sheet No. 1 quadrangle1:250000, 2 printings
• 1942 USGS Corona quadrangle1:62500, 2 printings
• 1942 USGS Corona and Vicinity quadrangle1:31680
• 1943 USGS Corona quadrangle1:62500
• 1947 USGS Santa Ana quadrangle1:250000
• 1949 USGS Santa Ana quadrangle1:250000
• 1954 USGS Corona North quadrangle1:24000, 2 printings
• 1956 USGS Santa Ana quadrangle1:250000
• 1959 USGS Santa Ana quadrangle1:250000, 3 printings
• 1960 USGS Santa Ana quadrangle1:250000, 2 printings
• 1965 USGS Santa Ana quadrangle1:250000
• 1967 USGS Corona North quadrangle1:24000, 6 printings
• 1975 USGS Corona North quadrangle1:24000
• 1983 USGS Santa Ana quadrangle1:100000

Regional context, not property-specific evidence. The federal wildfire occurrence database lists 558 fires within 5 miles of Porphyry between 1992 and 2020, burning about 35,347 acres in total. 3 started naturally. 51 were recorded as arson. Distance is straight-line from the map coordinates, so a fire counted here may appear on a neighbouring settlement's page as well.

The most recent of them, most recent first, with the day each was reported and the service that recorded it.

Settlements close enough to share some of these fires:

• Corona
• Home Gardens
• Pepper Corner
• May
• Norco
• Arlington Station

Every fire recorded in Riverside County

Regional context, not property-specific evidence. The federal mineral resources record lists 106 workings within 5 miles of Porphyry: 74 past producers, 11 producers, 10 prospects, 9 occurrences. 11 still produce. What was taken out: Clay, Stone, Crushed/Broken, Sand and Gravel, Construction, Gypsum-Anhydrite. Distance is straight-line from the map coordinates, so a quarry counted here may appear on a neighbouring settlement's page as well.

Every working recorded in Riverside County

The eight closest, with where each one stands in the county. Distances are straight-line, computed from the Geographic Names Information System coordinates.

Matched on this settlement's Geographic Names Information System number rather than its name, so it cannot be a different place of the same name in another state.

This settlement is recorded in the Geographic Names Information System as feature 1656600. The sheet list is computed by point-in-boundary test against the United States Geological Survey's historical topographic inventory. Both are works of the United States government and carry no copyright under 17 U.S.C. 105.

Wildfire. Short, Karen C. 2022. Spatial wildfire occurrence data for the United States, 1992-2020 [FPA_FOD_20221014]. 6th Edition. Fort Collins, CO: Forest Service Research Data Archive. https://doi.org/10.2737/RDS-2013-0009.6 Collected with United States Government funding and usable without additional permissions or fees.

Mines and quarries. USGS Mineral Resources Data System (MRDS) https://mrdata.usgs.gov/mrds/ A work of the United States government, no copyright under 17 U.S.C. 105.