Union, California

The same ground, surveyed 70 years apart. Drag the handle to wipe between them. Both sheets are United States Geological Survey originals; neither has been altered.

1919 1989

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.

• 1919 USGS Paso Robles quadrangle1:62500, 5 printings
• 1943 USGS Paso Robles quadrangle1:62500
• 1947 USGS San Luis Obispo quadrangle1:250000
• 1948 USGS Estrella quadrangle1:24000, 7 printings
• 1948 USGS Paso Robles quadrangle1:62500, 2 printings
• 1948 USGS San Luis Obispo quadrangle1:250000
• 1956 USGS San Luis Obispo quadrangle1:250000, 5 printings
• 1957 USGS San Luis Obispo quadrangle1:250000
• 1958 USGS San Luis Obispo quadrangle1:250000
• 1961 USGS Paso Robles quadrangle1:62500, 2 printings
• 1989 USGS Paso Robles quadrangle1:100000

Regional context, not property-specific evidence. The federal wildfire occurrence database lists 254 fires within 5 miles of Union between 1992 and 2020, burning about 1,070 acres in total. 3 started naturally. 7 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:

• Whitley Gardens
• Bern
• Linne

Every fire recorded in San Luis Obispo County

Regional context, not property-specific evidence. The federal mineral resources record lists 1 working within 5 miles of Union: 1 producer. All of them still produce. What was taken out: Sand and Gravel, Construction. 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 San Luis Obispo County

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

This settlement is recorded in the Geographic Names Information System as feature 1667686. 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.