Natural Science Exploration: Learning from Lewis and Clark

Lewis and Clark National Historical Park


[MUSIC PLAYING] In the fall of 1805, after traveling 3,700 miles over land and water, the Corps of Discovery, led by Lewis and Clark, arrived at the mouth of the Columbia River, in what is now part of Oregon and Washington. Here, they encountered the lush, temperate rainforest of the Pacific Coast, and established relations with the native peoples of the Lower Columbia River Region.

Fort Clatsop was constructed for winter quarters. And after settling in, the expedition went about exploring the area. President Thomas Jefferson instructed the expedition to make scientific observations. And the team spent hundreds of hours making detailed notes in their journals and collecting specimens.

These original observations from 1806 provide a snapshot of what the flora and fauna were like over 200 years ago. Modern scientists find this information invaluable for understanding how the landscape has changed. The National Park Service uses similar techniques today to understand the ecosystems in and around Lewis and Clark National Historical Park.

Lewis and Clark described dozens of animals and plants near Fort Clatsop, and carried nine herbarium samples with them on their return journey. Today, the park's herbarium includes samples of the same species, as well as 134 other specimens. Changes in forest and vegetation health can be more readily detected if you have a good understanding of the landscape as it was, and as it is now.

The National Park Service Inventory and Monitoring program conducted an inventory of plants, and created a vegetation map of the park. This field work, combined with computer analysis, produced a map with 21 vegetation types and three land cover types.

The park includes globally rare plant communities, such as Sitka Spruce Swamp, red fescue coastal headlands, Pacific reedgrass that lives on the cliffs above salty ocean spray, and marshes of Lyngby's sedge and Pacific silverweed. The map informs restoration actions, delineates wildlife habitat, and serves as a baseline to track changes over time.

While the vegetation map provides a one-time look at conditions, park staff also monitors how forests are changing over time. The forests include Sitka spruce, a long-lived species that grows only along a narrow band of the northwest coast of North America. Some of the trees that were alive during Lewis and Clark's visit are still living on park lands at Cape Disappointment.

Sitka spruce is vulnerable to rapid changes in its environment because of its limited growing conditions. National Park Service scientists are monitoring older Sitka spruce forests. The monitoring team is studying tree mortality, recruitment, and growth, through detailed, long-term observation.

These indicators of environmental change will help the team understand if the ecological integrity of these forests dating back to Lewis and Clark can persist into the future. The team's monitoring has provided managers with some good news. The Sitka spruce forests are healthy, and ecological indicators are within the range of natural conditions.

The abundance of Roosevelt elk was a critical factor in the party's decision to winter at Fort Clatsop. The Corps of Discovery shot 130 elk during that winter to replenish their supplies. Elk was their main source of food. And elk also provided hides for clothing and tallow for candles.

More than 200 years later, visitors to the park can see the descendants of those elk. Since 2008, the National Park Service, in collaboration with US Geological Survey, has been monitoring elk populations in the Fort Clatsop unit of the park, to detect changes in elk population and use of habitat.

There are multiple ways to count elk. Under a dense forest canopy, elk can be difficult to be seen by air or from the road. So the science team at Lewis and Clark head out into the forest to count elk droppings or pellets at a systematic grid of plots. Analyzing the results from neighboring plots produces a map that shows how elk are using different parts of the park over time, informing managers of key elk habitat.

Since elk cross property lines and boundaries at will, the park also conducts routine morning roadside surveys that encompass private and public lands outside the park. With rural and urban development that fragments the habitat, these methods help track how elk respond.

Using observation and science to monitor vital signs in the park is essential to the National Park Service's mission of preserving natural and cultural resources for the enjoyment of the American public. Counting elk, monitoring the health of old-growth spruce forests, and measuring the density and diversity of vegetation are just a few examples of how park scientists are measuring the status of park natural resources.

The early natural science work of Lewis and Clark right here at this location gave us valuable data about the nature of this place. The work that park scientists and managers are doing now helps to ensure the ecological integrity of this landscape into the future.



The National Park Service is grouped into 32 Inventory and Monitoring networks across the country which are tasked with gathering and analyzing information on park resources. In 2018, each network created a short film to showcase some of the science that is being done in our parks. For the North Coast Cascades Network, some of the monitoring work being conducted at Lewis and Clark National Historical Park was chosen as the subject of this short film. Park staff assisted filmmaker Michael Durham and NCCN I&M Program Manager Dr. Mark Huff in the creation of this film. In it, we highlight the traditions of scientific observation and data collection that began here with the journals of Lewis and Clark and continue today through the use of modern technologies.


6 minutes, 33 seconds


NCCN Inventory and Monitoring Program

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