Monrovia, California

The same ground, surveyed 101 years apart. Drag the handle to wipe between them. Both sheets are United States Geological Survey originals; neither has been altered.

1894 1995

Buildings and businesses the archive holds for this place. Each opens its own page, with the source record it came from.

On the National Register 5 records

• Upton Sinclair HouseNational Historic Landmark · listed 1971
• Aztec Hotellisted 1978
• Oaks, Thelisted 1978
• Luther and Adah Blair Houselisted 2024
• Brossart, John F. and Julia Houselisted 2024

Monrovia grew from 36,590 to 37,931 between 2010 and 2020. These are the recorded population figures Wikidata holds for this place, reached through the Geographic Names Information System number this page is keyed on rather than by name, so they belong to this place and not to another of the same name. Most are census counts, but not all are: an early figure may be a founding or settlement estimate, and an estimate published within five years of a census is left out. The change column is computed, and is left blank where more than 20 years separate a figure from the one before it, because a gap that long is not a change between two counts.

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.

• 1894 USGS Pomona quadrangle1:62500
• 1897 USGS Pomona quadrangle1:62500
• 1898 USGS Pomona quadrangle1:62500, 2 printings
• 1901 USGS Southern California Sheet No. 1 quadrangle1:250000, 6 printings
• 1904 USGS Pomona quadrangle1:62500, 7 printings
• 1904 USGS Southern California Sheet No. 1 quadrangle1:250000, 2 printings
• 1925 USGS Azusa quadrangle1:24000
• 1928 USGS Azusa quadrangle1:24000, 3 printings
• 1933 USGS Azusa quadrangle1:24000
• 1939 USGS Azusa quadrangle1:24000, 3 printings
• 1953 USGS Azusa quadrangle1:24000, 2 printings
• 1953 USGS San Bernardino quadrangle1:250000, 2 printings
• 1956 USGS San Bernardino quadrangle1:250000
• 1957 USGS San Bernardino quadrangle1:250000
• 1958 USGS San Bernardino quadrangle1:250000
• 1959 USGS San Bernardino quadrangle1:250000
• 1966 USGS Azusa quadrangle1:24000, 5 printings
• 1966 USGS San Bernardino quadrangle1:250000
• 1976 USGS Azusa quadrangle1:24000
• 1982 USGS San Bernardino quadrangle1:100000
• 1995 USGS Azusa quadrangle1:24000

Regional context, not property-specific evidence. The federal wildfire occurrence database lists 361 fires within 5 miles of Monrovia between 1992 and 2020, burning about 6,020 acres in total. 1 started naturally. 53 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:

• Cloverleaf Canyon
• Bradbury
• Butler
• Duarte
• Mayflower Village
• Arcadia

Every fire recorded in Los Angeles County

Regional context, not property-specific evidence. The federal mineral resources record lists 62 workings within 5 miles of Monrovia: 44 past producers, 8 prospects, 6 producers, 4 occurrences. 6 still produce. What was taken out: Sand and Gravel, Construction, Gold, Silver, Gold, 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 Los Angeles County

Regional context, not property-specific evidence. The National Weather Service names Monrovia in 1 storm report in 2000: 1 flood. No death or injury is recorded in these reports. Each account below is quoted exactly as the forecast office filed it, from the NOAA Storm Events Database, and each date opens the federal record of that event.

Every storm recorded in Los Angeles 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 1661049. 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.

Storms. NOAA National Centers for Environmental Information, Storm Events Database https://www.ncei.noaa.gov/stormevents/ A work of the United States government, no copyright under 17 U.S.C. 105. Narratives are quoted verbatim from the National Weather Service report and are not edited or summarised.