Twin Spruce, Colorado

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.

• 1899 USGS West Denver quadrangle1:125000
• 1906 USGS Blackhawk quadrangle1:62500, 5 printings
• 1942 USGS Eldorado Springs quadrangle1:24000, 4 printings
• 1944 USGS Eldorado Springs quadrangle1:31680, 2 printings
• 1953 USGS Denver quadrangle1:250000, 6 printings
• 1957 USGS Denver quadrangle1:250000
• 1958 USGS Denver quadrangle1:250000
• 1960 USGS Denver quadrangle1:250000
• 1965 USGS Eldorado Springs quadrangle1:24000, 8 printings
• 1983 USGS Denver West quadrangle1:100000, 2 printings

Regional context, not property-specific evidence. The federal wildfire occurrence database lists 113 fires within 5 miles of Twin Spruce between 1992 and 2020, burning about 1,150 acres in total. 25 started naturally. 1 was 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:

• Plainview

Every fire recorded in Jefferson County

Regional context, not property-specific evidence. The federal mineral resources record lists 31 workings within 5 miles of Twin Spruce: 11 occurrences, 10 producers, 7 past producers, 2 unknowns. 10 still produce. What was taken out: Gold, Uranium, Clay, Fire Clay (Refractory). 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 Jefferson 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 181168. 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.