Welcome to the Rock Creek Environmental Studies Center

Consisting of approximately 100 acres, the area protected as the Rock Creek Environmental Studies Center ( RCESC ) represents a mosaic of habitat types, including upland forests dominated by Douglas-fir and bigleaf maple, bottomland ash-forested wetlands, Oregon white oak woodlands, emergent wetlands, and wet prairies. Home to hundreds of species of wildlife and native plants, this site is a living laboratory for PCC students, hosts a multi-million dollar  floodplain enhancement project , and is open to the community for activities consistent with its designation as wildlife habitat.

The stream now known as Rock Creek originates in the forested western slopes of the Tualatin Mountains, meanders through wetlands and prairies converted to agricultural uses, and runs down through urban neighborhoods and under highways, to meet up with the Tualatin River at Rood Bridge Park in Hillsboro.

The Tualatin River watershed is the traditional territory of the Tualatin band of the Kalapuya tribe, and is part of the area included in the 1855 Treaty with the Confederated Tribes of the Willamette Valley. Today, the  Confederated Tribes of the Grand Ronde , composed over 30 tribes including the Kalapuya, maintain a connection with their homeland.

Treaties between the tribes and the United States government led to the forced removal of Indigenous people from their traditional territories. Under US federal law, this became public domain land, which could then be transferred to the states or to private ownership. Essential to this process of land transfer was the establishment of the General Land Office, which was responsible for surveying public domain lands using the Public Land Survey System.

In the region known as the Oregon Territory, under another law, the Donation Land Act of 1850, an office of Surveyor General of Oregon was established to survey the land and make gifts (donations) of 'public land' (at the time, unceded Indigenous territory) to settlers. Under the Act, each settler (white or 'half-breed'), who was or intended to become an American citizen, could receive land if they settled and cultivated the land. This accelerated the transfer of land ownership to European-American settlers and promoted agriculture in the Willamette Valley and Tualatin basin.

The cadastral surveys performed by the General Land Office (GLO) represent some of the earliest written maps available today. In the Oregon Territory, these surveys are tied to an initial point on the Willamette Meridian, often called the Willamette Stone. This survey marker is located in the West Hills of Portland and marks the delineation between north and south (Townships) and east and west (Ranges). Each combination of Township and Range (e.g. Township 1 North, Range 1 West) represents a 6 by 6 mile square area, further subdivided into 36 one-mile square sections. The Rock Creek Environmental Studies Center is located in T1N, R1W, Section 18. In addition to mapping property boundaries, surveyors noted physical features and vegetation observed on the landscape.

"Land rolling, Soil 2nd rate Sandy Loam, Timber Fir, Oak, Maple &c." - General Land Office notes from 1855 survey.

A process known as georeferencing was used to tie historical images of the site to the locations they represent. The 1855 GLO survey as well as historic aerial photographs of the site (from 1936 to 2012) were georeferenced using ArcGIS Pro software. Images were uploaded as raster files and the georeferencing tool was used to tie them to the correct location on Earth. NW 185th Ave serves as a valuable reference line, as it marks the boundary of the GLO survey map, and is clearly visible in all photographs. Also visible in all photographs is the 200+ year old Lone Oak tree, the riparian corridor along Rock Creek, as well as upland forest patches. Use the following swipe function to see how the landscape changes over time by moving the arrow slider from left to right. The historic aerial images are shown on a basemap of 2020 aerial imagery.

The location of the Rock Creek Environmental Studies Center influences the past, current, and future changes in land use. This is a partial overview of some of that history.

The Kalapuya people have lived in the Willamette and Umpqua valleys for over 14,000 years and once occupied more than a million acres of territory. The Tualatin band of Kalapuya, also known as the Atfalati, occupied the Tualatin watershed (Lewis 2022). The Kalapuya people actively managed the landscape through burning of brush and forests to encourage growth of important food plants, such as Oregon white oak, camas, and tarweed. This regular disturbance helped to maintain a mosaic of open oak woodland, savanna, and prairie communities. Contact with European-Americans and the introduction of diseases such as smallpox (1790's) and later malaria (1829), decimated the Kalapuya population (Lewis 2022). The reduced numbers of Kalapuya people made it harder for them to resist European-American settlers who took their land and dramatically altered the management of the land. As mentioned above, US federal policies accelerated this process.

By the time that the General Land Office surveyors mapped the Willamette and Tualatin Valleys in the 1850's, much of the land had been claimed, and altered, by European-American settlers who actively suppressed fire and introduced new types of agriculture. Over time, many wetlands were drained to allow more area for grazing cattle and growing introduced crops, and forests were logged to provide timber for a growing population. In the late 20th century, many of these agricultural areas were converted to suburban housing developments.

Oregon's comprehensive land use laws, first instituted in the 1970's, have also influenced patterns of development and the resulting vegetative cover. The RCESC is on the western edge of the Portland Metro Urban Growth Boundary and is part of unincorporated Washington County, and therefore not covered by any city ordinances. Washington County is home to many high-tech companies and other major employers, and the population has been growing rapidly for the past several decades. Oregon land use law requires that cities update the Urban Growth Boundary to allow for population growth, and the Portland Metro UGB has been extended multiple times. Urban development occurs within the UGB, with the goal of linking development to transportation, and protecting farmland, forest, and natural areas.

In this growing metropolitan region, we are seeing loss of tree canopy and increased wetland fragmentation and loss, as a result of increased demand for housing, especially single family homes which require more land than higher density infill housing within the city. Recent construction within the Urban Growth Boundary has impacted the forests and wetlands of the Rock Creek Environmental Studies Center, even as we work to restore wetland habitat on our site.

The feature layers used for GPS data collection include photopoint monitoring locations (points), wildlife cameras (points), points of interest (points), trails (lines), and study areas (polygons). The fields for data collection included names or numbers, notes, descriptions of location, and attachments (photographs). Additional geographic features will be added as this project evolves.

There are several established trails leading through the Rock Creek Environmental Studies Center. Maps are posted at the eastside and westside forest entrances, along with boot brushes for cleaning shoes to help prevent spread of invasive plant species. There is a farm road which is used for moving cows to pasture and allows for vehicle access during the dry season. Trail signs were installed in 2019 and funded by a PCC EcoSocialJustice grant. Signage could be improved and enhanced with further funding.

There are 19  photopoint monitoring sites  located throughout the RCESC. Beginning in 1998, faculty and students have taken photographs four times per year, once every season, at fixed points and compass headings. These photographs show changes in vegetation structure and composition over time, as well as broader changes in landscape and hydrology.

Since 2018, several infrared, motion detecting Reconyx wildlife cameras have been taking photographs at fixed locations in the RCESC. These cameras were funded by a grant from the Community College Undergraduate Research Initiative (CCURI). These locations are noted as points on the map and numbered from 1 to 5. In general, the cameras are running year round, activated by motion coupled with detection of warm objects against a cooler background. These work best for detecting large mammals and birds. The five cameras face out into the wetlands to capture both resident and migratory animals. PCC students help to organize and analyze these observations and share their results with the wider community.

Discrete, ongoing research study areas are shown as polygons on the map. There is an opportunity to add more locations in the future, and not all research is represented as many studies collect data at multiple, dispersed locations in the Rock Creek Environmental Studies Center.

Interesting locations are highlighted as points of interest on the map. In the future, there will be opportunities for students and community members to add their own observations.

For this project, higher accuracy GPS receivers (Bad Elf, Trimble Catalyst DA2) were used to create maps of the trail systems and data collection points. In the future, students and community members can use GPS receivers integrated into tablets or mobile phones and apps such as Esri Collector or Field Maps (available to all PCC faculty, staff, and students) to collect and share data from specific locations in the Rock Creek Environmental Studies Center.

Here is an overview of the workflow used to collect and share this data. For future project, make sure to consider the data that will be collected, and take time to set the project up using a desktop before heading out into the field.

The GPS data collected for this project can be viewed using the interactive map shown below. You can select different layers (three stacked squares), view the legend (three stacked lines), and see photographs of each feature.

Potential improvements for access and use: Do you have ideas for improvements to trails, signage, etc., or suggested amenities (e.g., sitting areas)? Please share! 

“Signs would help a lot. A map showing slope of trail and notes about surface might help people decide if it is a comfortable place for them to visit.” – Tualatin Hills Parks and Recreation District staff

"Interpretive signs to explain the ecological and cultural significance of oak, prairie, and wetlands would be really cool.” – Tualatin Soil and Water Conservation District

“Signage in various languages, including Indigenous languages”. – PCC alumni and Indigenous community member

Desired future condition and uses: This natural area is always in a state of change, and we are working to enhance wildlife habitat, ecosystem functions, and ecological conditions in the face of increased development, and climate change. What would you like to see here in the future? What practices, habitats, species, etc. would you like to see encourages (or discouraged) at this site?

Restore native plants, study native ecosystems.” –OSU professor and native person of the area.

 “Harvesting and traditional ecological healing practices, stewardship activities. Guided hikes.” –PCC alumni and Indigenous community member

“I would love to preserve the area as much as possible while educating others about the importance of creating ecosystems like this one throughout the city to create wildlife habitat.” –PCC Student

"Controlled burning and prescribed fire for cultural objectives.” –PCC alumni and Indigenous community member 

“Activities that support a co-stewarding approach including encouraging cultural practices by the indigenous community.” -Clean Water Services Rock Creek floodplain project manager.

“Continue to manage the non-woodland areas as prairie.  This will require semi-annual disturbances like fire, mowing, or cattle grazing to keep woody trees and shrubs from moving in to those areas.” –Tualatin Soil and Water Conservation District staff

Re-naming the site? The Rock Creek Environmental Studies Center is a long and non-descriptive name for this site! Do you have suggestions for a shorter and more meaningful name? Examples include “Rock Creek Woods and Wetlands” and “Rock Creek Refuge”. Please share your ideas.

Names honoring the Indigenous people of the area suggested by Indigenous members of the PCC Oaks Partnership: Kalapuya Creek and Atfalati Wetlands

“I like woods/wetlands. Consider the role of public access- the title could help people know if they are welcome to visit. Is it geared towards student studies or anyone who wants to walk here?” -THPRD staff

This is part of an ongoing project to document, share, and plan for the future of the Rock Creek Environmental Studies Center. My hope is that this visual storytelling can help people imagine how we might take care of this site for future generations. Here are some ideas for future work:

• Interactive trail maps that can be used to aid in navigation/provide a guided tour of the site.
• Public data collection options for students and community members to add observations (e.g., data collected during field labs, community science).
• More use of data visualization and visual storytelling to communicate with a broader audience.
• Use our understanding of the site history, paired with current conditions and projections (climate change, population growth), to develop plans for continued protection, restoration, and outreach.
• Participatory mapping of the site with community members and partners to envision preferred futures.