BLM Submissions

Lidar and aerial photography are valuable tools for preliminary investigations by cadastral surveyors.  Boundary disputes are often decided using survey information.  Remote sensing data provide a visual presentation of the ground conditions, to help interpret the situation.  Historical aerial photography, satellite imagery, and lidar data combined with ground survey data provide clues to surveyors investigating trespass, boundary issues, and other situations dealing with monument lands.  Remote sensing investigations may drive the need for field surveys or provide enough information to res

The famous Laetoli footprints were made by a human ancestor 3.56 million years ago in the Rift Valley of Tanzania and are the earliest fossil evidence of bipedalism in our ancestors.  The trail of 70 tracks found in 1976, are believed to correspond to an Australopithecus afarensis. The tracks were covered for protection after initial investigations.  At the request of the Tanzanian government a partial re-excavation of the site was conducted in February of 2011 to evaluate the preservation of the buried footprint trail and to get samples for further scientific studies.

BLM has issued a National sage grouse policy to ensure environmentally responsible exploration, authorization, leasing and development of energy resources within the range of the Gunnison sage-grouse.   To support the Colorado State Office and the Gunnison Field Office, the BLM acquired lidar and airborne digital imagery for approximately 30,000 acres in the Gunnison basin. In 2011 lidar data were acquired at 8 - 10 points per square meter density and used to create highly accurate bare earth elevation models and representations of sagebrush vegetation structure.

The Oregon BLM State Office developed a semi-automated technique to map juniper distribution for specific project areas.  The technique uses 0.5 meter color infra-red NAIP imagery to identify juniper vegetation and map individual trees.  The maps are used to plan for field activities such as fuel treatments and habitat restoration.

The Pacific Northwest Hydrography Framework is sponsoring a working group tasked to evaluate the use of lidar-derived DEMs as a principal data source for updating the National Hydrology Database (NHD). The working group has identified a workflow leading to the acceptance of revisions to the national stream network dataset.

The revised Statue 2477 (RS2477) was enacted by Congress in 1866 to facilitate western settlement.  It granted “the right-of-way for the construction of highways across public lands not otherwise reserved for public purposes…” There was no requirement to legally record the right of way. Mere existence and use of the road established a legal right of way.   This statue was repealed in 1976 with the provision to honor “valid existing rights.” Legal disputes have ensued regarding what routes qualify as a valid existing right of way.