The Route No. 1 Overton-Lake Mead Road contributed significantly to National Park Service development of the Lake Mead National Recreation Area beginning in Low water crossings were constructed as key elements of the road, to allow water to pass over the roadway during episodes of flash flooding without eroding the road embankment. Report Prepared By: Kurt Schweigert Associated Cultural Resource Experts (ACRE) Littleton, Colorado Date: September ROUTE NO. 1 OVERTON-LAKE MEAD ROAD, LOW WATER CROSSINGS (Northshore Road, Overton Beach Access Road) HAER No. Page2 I. Description Route No. 1 Overton-Lake Mead Road (Route No. 1) was constructed in to provide access to Overton Beach, a recreation facility within the Boulder Dam Recreation Area (now the Lake Mead National Recreation Area).
The documented portion of Route No. 1 extends from Overton Beach southwestward and then northwestward about 6.2 miles to the boundary of the Lake Mead National Recreation Area. The documented segment of Route No. 1 includes two low water crossing structures that allowed water to pass over the roadway and down an inclined spillway, effectively protecting the down slope side of the highway embankment from erosion. The two low water crossing structures (Features 118 and 146 on the attached map) appear to have nearly identical construction, but Low Water Crossing 146 is mostly buried or was removed during reconstruction of the highway. II. Architectural and Engineering Information Low Water Crossing 118 is nearly entirely intact.
The structure has two parallel walls constructed of sandstone blocks and concrete mortar; the upper wall is at the level of and adjacent to the edge of the highway pavement on the down slope (east) side of the highway embankment, and the lower wall is located 24' to the east and at a lower elevation than the upper wall. Only the cap of the upper wall is exposed. The upper wall is long and is uniform sandstone blocks 16" to 18" wide and 18" long, with long axis perpendicular to the highway centerline. The exposed lower wall rises 2' to 2' 6" above the drainage bottom. The lower wall is 61 feet long, is constructed of sandstone rubble and concrete to a height of about 2 ', and then is capped with regular sandstone blocks approximately 6" thick, 16" to 18" long, and 10" to 12" wide.
Unlike the upper wall, the cap stones of the lower wall are set with long axis parallel to the highway centerline. The northwest end of the lower wall rises in a shoulder approximately 9" above the rest of the wall, where the wall meets the drainage escarpment. The inclined spillway area between the upper and lower walls is dry-laid sandstone rubble approximately 18" deep. Approximately 6" of asphalt overlays the riprap; the asphalt appears to have been laid in a single episode. Low Water Crossing 146 is located near the intersection of the Overton Beach Access Road and the North Shore Road segments of Route No. 1. The road in this area has been substantially re-aligned, including installation of a series oflarge steel culverts to carry water under the current roadway.
Only the top or cap of the apparent downstream masonry wall of the original low water crossing is exposed. The exposed cap is 98' long and is constructed of dark red sandstone blocks approximately 18" square and concrete mortar. A large asphalt apron extends down slope to the northeast of the masonry wall. A dike with flanking ditches extends from the east of the end of the exposed masonry wall. III. History The low water crossings along the documented segment of Route No. 1 were built by a contractor for the Bureau of Public Roads in and these features are indicated on as-built drawings of Route No. 1 (National Park Service Construction of Route No. 1 is extensively discussed in the Historical Data section ofHAER-NV-40.
Please also see written and historical data for HAER-NV-40-A (Route No. 1 Culverts and Headwalls), HAER-NV-40-B (Route No. 1 Gutters), HAER-NV-40-C (Route No. 1 Diversion Dikes and Ditches), and HAER NV-40-E (Route No. 1 Station Markers). IV. Sources Blalack, JoAnn Overton Beach Road Survey of Route 1 Overton-Lake Mead Highway Station Markers. National Park Service, Western Archeological and Conservation Center, Tucson, Arizona. ROUTE NO. 1 OVERTON-LAKE MEAD ROAD, LOW WATER CROSSINGS (Northshore Road, Overton Beach Access Road) HAER No. Page 3 Cassell, J. T. Final Construction Report, Grading and Bituminous Treated Surfacing on Section A of Route 1 Overton-Lake Mead Boulder Dam Recreational Area Clark County, Nevada. Daron, Steven E.
Replacement of a Culvert Along Overton Beach Access Road, Lake Mead National Recreation Area, Clark County, Nevada. Submitted to Lake Mead National Recreation Area, Boulder City, Nevada. WACCProject#LAME Federal Highway Administration Report on Existing Headwalls Built by the Civilian Conservation Corps circa Northshore Road and Overton Beach Road. Lake Mead National Recreation Area, Nevada Projects PRA- LAME & PRA-LAME Prepared by the Department of Transportation, Federal Highway Administration, Central Federal Lands Highway Division, Denver, Colorado. National Park Service Project 1-A, Grading and Bituminous Treated Surfacing Route No. 1- Overton-Lake Mead, Boulder Dam Recreational Area Highway System, Arizona & Nevada.
On file at National Park Service, Lake Mead National Recreation Headquarters, Boulder City, Nevada. V. Project Information This documentation has been prepared at the request of the National Park Service, Lake Mead National Recreation Area. In NPS and the Nevada State Historic Preservation Office (NV-SHPO) agreed that repair or maintenance could adversely affect historic drainage structures along Route No. 1. A Memorandum of Agreement (MOA) between NPS and NV-SHPO stipulated that HAER documentation would be accomplished for features along Route No. 1 prior to reconstruction of the road. This HAER documentation partially fulfills requirements of the MOA.
This documentation was accomplished by Associated Cultural Resource Experts (ACRE) under provisions of a task order issued by the National Park Service to Scientific Applications International Corporation (SAIC). Kurt P. Schweigert of ACRE was Principal Investigator and prepared the second draft and final documentation packages. Douglas M. Edwards and Kurt P. Schweigert of ACRE were the photographers, and Peggy Beedle of ACRE accomplished most of the research and initial field documentation. Melissa Johnson of ACRE assisted in field documentation and photography. Field documentation and photography were accomplished in February and February This documentation was based in part on three previous field surveys of drainage features and survey monuments along Route No.
1 (Daron Blalack Federal Highway Administration Lake Mead National Recreation Area staff provided copies of plans for Route 1 and other materials. Additional information was obtained from the National Park Service Technical Information Center in Denver, Colorado; Special Collections at the Lied Library at the University ofNevada-Las Vegas; and the National Archives in College Park, Maryland. Boulder City, Nevada historian Dennis McBride provided a newspaper index on road articles from local newspapers. ROUTE NO. 1 OVERTON-LAKE MEAD ROAD, LOW WATER CROSSINGS (Northshore Road, Overton Beach Access Road) HAER No. Page4 ... ~ t.. ('IS :Es C) ... ,:: :: .5 (I) O> 0 :.> 1/) >a,-;;::,,Ul -. -m->O - ::s (I') 0 (!) - ... 0 II II II II II ><
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