Infrastructure, such as roads, airports, water and energy transmission and distribution facilities, sewage treatment plants, and many other facilities, is vital to the sustainability and vitality of any populated area. Rehabilitation of existing and development of new infrastructure requires three natural resources: natural aggregate (stone, sand, and gravel), water, and energy http://rockyweb.cr.usgs.gov/frontrange/overview.htm.

The principal goals of the U.S. Geological Survey (USGS) Front Range Infrastructure Resources Project (FRIRP) were to develop information, define tools, and demonstrate ways to: (1) implement a multidisciplinary evaluation of the distribution and quality of a region's infrastructure resources, (2) identify issues that may affect availability of resources, and (3) work with cooperators to provide decision makers with tools to evaluate alternatives to enhance decision-making. Geographic integration of data (geospatial databases) can provide an interactive tool to facilitate decision-making by stakeholders http://rockyweb.cr.usgs.gov/frontrange/overview.htm.

In 2018, the Golden Gate National Parks Conservancy (Parks Conservancy) (https://parksconservancy.org), non-profit support partner to the National Park Service (NPS) Golden Gate National Recreation Area (GGNRA), initiated a fine scale vegetation mapping project in Marin County. The GGNRA includes lands in San Francisco and San Mateo counties, and NPS expressed interest in pursuing fine scale vegetation mapping for those lands as well. The Parks Conservancy facilitated multiple meetings with potential project stakeholders and was able to build a consortium of funders to map all of San Mateo County (and NPS lands in San Francisco). The consortium included the San Francisco Public Utilities Commission (SFPUC), Midpeninsula Regional Open Space District (MROSD), Peninsula Open Space Trust (POST), San Mateo City/County Association of Governments, and various County of San Mateo departments including Parks, Agricultural Weights and Measures, Public Works/Flood Control District, Office of Sustainability, and Planning and Building. Over a 3-year period, the project, collectively referred to as the “San Mateo Fine Scale Veg Map”, has produced numerous environmental GIS products including 1-foot contours, orthophotography, and other land cover maps. A 106-class fine-scale vegetation map was completed in April 2022 that details vegetation communities and agricultural land cover types, including forests, grasslands, riparian vegetation, wetlands, and croplands. The environmental data products from the San Mateo Fine Scale Veg Map are foundational and can be used by organizations and government departments for a wide range of purposes, including planning, conservation, and to track changes over time to San Mateo County''s habitats and natural resources.Development of the San Mateo fine-scale vegetation map was managed by the Golden Gate National Parks Conservancy and staffed by personnel from Tukman Geospatial (https://tukmangeospatial.com/), Aerial Information Systems (AIS; http

The Tamalpais Lands Collaborative (One Tam; https://www.onetam.org/), the network of organizations that manage lands on Mount Tamalpais in Marin County, initiated the countywide mapping project with their interest in creating a seamless, comprehensive map depicting vegetation communities across the landscape. With support from their non-profit partner the Golden Gate National Parks Conservancy (https://www.parksconservancy.org/) One Tam was able to build a consortium to fund and implement the countywide fine scale vegetation map.Development of the Marin fine-scale vegetation map was managed by the Golden Gate National Parks Conservancy and staffed by personnel from Tukman Geospatial (https://tukmangeospatial.com/) Aerial Information Systems (AIS; http://www.aisgis.com/), and Kass Green and Associates. The fine-scale vegetation map effort included field surveys by a team of trained botanists. Data from these surveys, combined with older surveys from previous efforts, were analyzed by the California Native Plant Society (CNPS) Vegetation Program (https://www.cnps.org/vegetation) with support from the California Department of Fish and Wildlife Vegetation Classification and Mapping Program (VegCAMP; https://wildlife.ca.gov/Data/VegCAMP) to develop a Marin County-specific vegetation classification.High density lidar data was obtained countywide in the early winter of 2019 to support the project. The lidar point cloud, and many of its derivatives, were used extensively during the process of developing the fine-scale vegetation and habitat map. The lidar data was used in conjunction with optical data. Optical data used throughout the project included 6-inch resolution airborne 4-band imagery collected in the summer of 2018, as well as 6-inch imagery from 2014 and various dates of National Agriculture Imagery Program (NAIP) imagery.In 2019, a 26-class lifeform map was produced which serves as the foundation for the much more floristically detailed fine-scale vegetation and habitat map. The lifeform map was developed using expert systems rulesets in Trimble Ecognition®, followed by manual editing.In 2019, Tukman Geospatial staff and partners conducted countywide reconnaissance fieldwork to support fine-scale mapping. Field-collected data were used to train automated machine learning algorithms, which produced a fully automated countywide fine-scale vegetation and habitat map. Throughout 2020, AIS manually edited the fine-scale maps, and Tukman Geospatial and AIS went to the field for validation trips to inform and improve the manual editing process. In the spring of 2021, draft maps were distributed and reviewed by Marin County's community of land managers and by the funders of the project. Input from these groups was used to further refine the map. The countywide fine-scale vegetation map and related data products were made public in June 2021. In total, 107 vegetation classes were mapped with a minimum mapping size of one fifth to one acre, varying by class.Accuracy assessment plot data were collected in 2019, 2020, and 2021. Accuracy assessment results were compiled and analyzed in the summer of 2021. Overall accuracy of the lifeformmap is 95%. Overall accuracy of the fine-scale vegetation map is 77%, with an overall 'fuzzy' accuracy of 81%.The Marin County fine-scale vegetation map was designed for a broad audience for use at many floristic and spatial scales. At its most floristically resolute scale, the fine-scale vegetation map depicts the landscape at the National Vegetation Classification alliance level - which characterizes stands of vegetation generally by the dominant species present. This product is useful to managers interested in specific information about vegetation composition. For those interested in general land use and land cover, the lifeform map may be more appropriate. Tomake the information contained in the map accessible to the most users, the vegetation map is published as a suite of GIS deliverables available in a number of formats. Map products are being made available wherever possible by the project stakeholders, including the regional data portal Pacific Veg Map (http://pacificvegmap.org/data-downloads).

The map and descriptions offer information that may be used for: land-use planning (e.g. selecting land fill sites, greenbelts, avoiding geologic hazards), for finding aggregate resources (crushed rock, sand, and gravel), for study of geomorphology and Quaternary geology. Geologic hazards (e.g., landslides, swelling soils, heaving bedrock, and flooding) known to be located in, or characteristic of some mapped units, were identified.

Surficial deposits in the quadrangle partially record depositional events of the Quaternary Period (the most recent 1.8 million years). Some events such as floods are familiar to persons living in the area, while other recorded events are pre-historical. The latter include glaciation, probable large earthquakes, protracted drought, and widespread deposition of sand and silt by wind. At least twice in the past 200,000 years (most recently about 30,000 to 12,000 years ago) global cooling caused glaciers to form along the Continental Divide. The glaciers advanced down valleys in the Front Range, deeply eroded the bedrock, and deposited moraines (map units tbg, tbj) and outwash (ggq, gge). On the plains (east part of map), eolian sand (es), stabilized dune sand (ed), and loess (elb) are present and in places contain buried paleosols. These deposits indicate that periods of sand dune deposition alternated with periods of stabilized dunes and soil formation.

Thirty-nine types of surficial geologic deposits and residual materials of Quaternary age are described and mapped in the greater Denver area, in part of the Front Range, and in the piedmont and plains east of Denver, Boulder, and Castle Rock. Descriptions appear in the pamphlet that accompanies the map. Landslide deposits, colluvium, residuum, alluvium, and other deposits or materials are described in terms of predominant grain size, mineral or rock composition (e.g., gypsiferous, calcareous, granitic, andesitic), thickness of deposits, and other physical characteristics. Origins and ages of the deposits and geologic hazards related to them are noted. Many lines between geologic units on our map were placed by generalizing contacts on published maps. However, in 1997-1999 we mapped new boundaries, as well. The map was projected to the UTM projection. This large map area extends from the Continental Divide near Winter Park and Fairplay ( on the west edge), eastward about 107 mi (172 km); and extends from Boulder on the north edge to Woodland Park at the south edge (68 mi; 109 km).

Compilation scale: 1:250,000. Map is available in digital and print-on-demand paper formats. Deposits are described in terms of predominant grain size, mineralogic and lithologic composition, general thickness, and geologic hazards, if any, relevant geologic historical information and paleosoil information, if any. Thirty- nine map units of deposits include 5 alluvium types, 15 colluvia, 6 residua, 3 types of eolian deposits, 2 periglacial/disintegrated deposits, 3 tills, 2 landslide units, 2 glaciofluvial units, and 1 diamicton. An additional map unit depicts large areas of mostly bare bedrock.

The physical properties of the surficial materials were compiled from published soil and geologic maps and reports, our field observations, and from earth science journal articles. Selected deposits in the field were checked for conformity to descriptions of map units by the Quaternary geologist who compiled the surficial geologic map units.

FILES INCLUDED IN THIS DATA SET:

denvpoly: polygon coverage containing geologic unit contacts and labels. denvline: arc coverage containing faults. geol_sfo.lin: This lineset file defines geologic line types in the geologically themed coverages. geoscamp2.mrk: This markerset file defines the geologic markers in the geologically themed coverages. color524.shd: This shadeset file defines the cmyk values of colors assigned to polygons in the geologically themed coverages.