Videos

Permanent Control Site: GP1 West Transect; Depth: 7.9 m (25.9 feet); Distance from river mouth: 19.0 Kilometers (11.8 Miles) east; Pre/Post Dam Removal: 5 years post-dam removal; Lat/Long: 48.11852521,-123.31605203; Site Description: This site was established as the eastern control. Depth is medium-shallow.

Permanent Control Site: GP2 East Transect; Depth: 13.2 Meters (43.4 Feet); Distance from river mouth: 18.8 Kilometers (11.7 Miles) east; Pre/Post Dam Removal: 5 years post-dam removal; Lat/Long: 48.12781102,-123.31645664; Site Description: This site was established as the eastern control. Substrate is mainly a gravel sand mixture.

Permanent Site: H1 West Transect; Depth: 5.7 Meters (18.7 Feet); Distance from river mouth: 2.4 Kilometers (1.5 Miles) east; Pre/Post Dam Removal: 5 years post-dam removal; Lat/Long: 48.14803012,-123.53535558; Site Description: This is a shallow site and one of the farthest removed from the effects of the sediment plume outside of the control sites.

Permanent Site: C2 West Transect; Depth: 16.5 Meters (54.2 Feet); Distance from river mouth: 0.7 Kilometers (0.5 Miles); Pre/Post Dam Removal: 5 years post-dam removal; Lat/Long: 48.147841,-123.57663268; Site Description: One of our deepest sites. Substrate is all muddy sand. Seaweed is absent. Woody debris is present (1:18 seconds).

Permanent Site: A2 West Transect; Depth: 13.2 Meters (43.2 Feet); Distance from river mouth: Kilometers 1.8 (1.1 Miles); Pre/Post Dam Removal: 5 years post-dam removal; Lat/Long: 48.14130295, -123.5883331; Site Description: One of our deeper sites at over 40 feet. Sediment is primarily sand/sandy mud with scattered boulders.

Permanent Site: H1 East Transect; Depth: 5.7 Meters (18.8 Feet); Distance from river mouth: 2.4 Kilometers (1.5 Miles) east; Pre/Post Dam Removal: 5 years post-dam removal; Lat/Long: 48.1479177,-123.53472865; Site Description: This is a shallow site and one of the farthest removed from the effects of the sediment plume outside of the control sites.

Permanent Site: L1 West Transect; Depth: 11.1 Meters (36.5 Feet); Distance from river mouth: 2.3 Kilometers (1.4 Miles) west; Pre/Post Dam Removal: 5 years post-dam removal; Lat/Long: 48.13957527,-123.59427175; Site Description: This transect is medium depth. The first 20 meters contains scattered boulders (0:17 seconds).

Permanent Site: C2 East Transect; Depth: 16.1 Meters (52.8 Feet); Distance from river mouth: 0.7 Kilometers (0.4 Miles); Pre/Post Dam Removal: 5 years post-dam removal; Lat/Long: 48.147841,-123.57596074; Site Description: One of our deepest sites. Substrate is all muddy sand. Seaweed is absent.

Permanent Site: H2 West Transect; Depth: 7.8 Meters (25.5 Feet); Distance from river mouth: 2.6 Kilometers (1.6 Miles) east; Pre/Post Dam Removal: 5 years post-dam removal; Lat/Long: 48.15008216,-123.53277857; Site Description: This site is medium to shallow depth.

Permanent Site: A1 East Transect; Depth: 8.0 Meters (26.1 Feet); Distance from river mouth: 1.8 Kilometers (1.1 Miles) West; Pre/Post Dam Removal: 5 years post-dam removal; Lat/Long: 48.13870775, -123.5855312; Site Description: Transect is in eastern part of Freshwater Bay. Sediment is primarily sand/sandy mud. Previous small boulders appear to be buried.

Permanent Site: A1 West Transect; Depth: 9.0 Meters (29.6 Feet); Distance from river mouth: 1.9 Kilometers (1.2 Miles) West; Pre/Post Dam Removal: 5 years post-dam removal; Lat/Long: 48.13870775, -123.586203; Site Description: Transect is in eastern part of Freshwater Bay. Sediment is primarily sand/sandy mud with patches of boulders. Seaweeds are common this year.

Permanent Site: H2 East Transect; Depth: 8.1 Meters (26.6 Feet); Distance from river mouth: 2.6 Kilometers (1.6 Miles) east; Pre/Post Dam Removal: 5 years post-dam removal; Lat/Long: 48.15008216,-123.53210661; Site Description: This site is medium to shallow depth.

Permanent Site: 4SP1 - East Transect; Depth: 5.2 Meters (17.0 Feet); Distance from river mouth: 0.8 Kilometers (0.5 Miles) East; Pre/Post Dam Removal: 4 years post-dam removal; Lat/Long: 48.15257, -123.556704; Site Description: The site has converted from gravel/cobble substrate to all sand. Seaweed is completely absent. 
 

Permanent Site: 4SP1 - West Transect; Depth: 6.1 Meters (19.9 Feet); Distance from river mouth: 0.8 Kilometers (0.5 Miles) East; Pre/Post Dam Removal: 3 years post-dam removal; Lat/Long: 48.15257, -123.557376; Site Description: The site has converted from gravel/cobble substrate to all sand. Seaweed is completely absent. 
 

Permanent Site: C1 East Transect; Depth: Meters (Feet); Distance from river mouth: 0.7 Kilometers (0.4 Miles); Pre/Post Dam Removal: 5 years post-dam removal; Lat/Long: 48.14525225,-123.57294101; Site Description: Substrate is entirely sand. All seaweeds are absent. Woody debris is present (0:26, seconds).

Permanent Site: C1 West Transect; Depth: Meters (Feet); Distance from river mouth: 0.7 Kilometers (0.4 Miles); Pre/Post Dam Removal: 5 years post-dam removal; Lat/Long: 48.14525225,-123.57361291; Site Description: Substrate is entirely sand. All seaweeds are absent. Woody debris is present (0:12, 1:49 seconds).

Twenty middle-school girls from Washington and Oregon participated in the 2016 “GeoGirls” outdoor volcano science program at Mount St. Helens, jointly organized by the U.S. Geological Survey and the Mount St. Helens Institute. 

Permanent Site: C1 East Transect; Depth: Meters (Feet); Distance from river mouth: 0.7 Kilometers (0.4 Miles); Pre/Post Dam Removal: 2 years post-dam removal; Lat/Long: 48.14525225,-123.57294101; Site Description: Substrate is entirely sand. All seaweeds are absent.

Permanent Site: K1 East Transect; Depth: 6.2 Meters (20.5 Feet); Distance from river mouth: 4.5 Kilometers (2.8 Miles) east; Pre/Post Dam Removal: 5 years post-dam removal; Lat/Long: 48.13592923,-123.5101581; Site Description: This is a shallow site. Sediment is a gravel/sand mixture.

Permanent Site: K1 West Transect; Depth: 5.6 Meters (18.4 Feet); Distance from river mouth: 4.5 Kilometers (2.8 Miles) east; Pre/Post Dam Removal: 5 years post-dam removal; Lat/Long: 48.13592923,-123.51082988; Site Description: This is a shallow site. Sediment is a gravel/sand mixture.

Permanent Site: A2 East Transect; Depth: 12.6 Meters (41.5 Feet); Distance from river mouth: Kilometers 1.8 (1.1 Miles); Pre/Post Dam Removal: 5 years post-dam removal; Lat/Long: 48.14130295, -123.58766124; Site Description: One of our deeper sites at over 40 feet. Sediment is primarily sand/sandy mud.