Lower Rio Grande Study 

To see the complete Study, click here.

In 2006 the US Congress designated 33 miles of the Rio Grande in Colorado as the Rio Grande Natural Area (RGNA). This Natural Area extends from the south edge of the Alamosa National Wildlife Refuge to the Colorado/New Mexico State Line following the river, with an average width of approximately 1⁄2 mile. Land ownership within the RGNA is primarily Federal (BLM) and private parcels. This 33-mile reach of the Rio Grande is home to spectacular wildlife and historical resources, and remains relatively undeveloped.

Project Background

Assessment Discription

The 35 mile study area was divided into 5 reaches. Reach locations were determined for a variety of reasons including changes in landform, land use, geomorphic characteristics, accessibility, and others. 

Rio Grande Natural Area

​​Rio Grande Natural Area: River Condition Assessment 

The study covers a 33-mile stretch of the Rio Grande within the Rio Grande Natural Area (RGNA). Designated in 2006, the RGNA extends from the south edge of the Alamosa National Wildlife Refuge south to the Colorado/New Mexico State Line, this reach of the Rio Grande is home to spectacular wildlife and historical resources, and remains relatively undeveloped. 

The Lower Rio Grande Study includes map level assessments of land use, land ownership, riparian vegetation condition, and critical habitat designations for certain threatened and endangered species. It also includes field level measurements of river cross sections, sediment sizes, geomorphic condition, bank stability, water flow rates, and water quality. Observations of fish species and fish populations were made, and data on macro-invertebrate species was 

With this information, the report prioritizes areas in need of restoration. The finished report is intended to inform the RGHRP, BLM and the RGNA Commission on future restoration efforts.

Project Map

In 2001, the RGHRP authorized a study of the Rio Grande between South Fork and Alamosa. The purpose of the 2001 study was to assess current conditions in the river, and to identify and prioritize locations where restoration efforts are needed. 

This report has a similar purpose, but within the RIo Grande Natural Area (RGNA) section of the river. This 2015 study effort has been led by the RGHRP, with cooperation and partial funding by the BLM (Colorado office), with additional funding provided by a grant from Colorado Healthy Rivers Fund and the Sangre de Cristo National Heritage Area.