Recently, an enthusiastic high school student suggested that Friends of the Hylebos develop a program to restore bears and cougars to the wilds of Federal Way.

I could’ve discussed the ecological reasons those two top predators could no longer survive sustainably in the natural habitat that remains in and around the city. Instead, I zeroed in on the challenges in the political ecology. Some animals, I pointed out, tend to be unpopular in cities. This usually includes any animal that would likely eat its citizens.

For the record, I don’t think I was successful in changing his mind. However, the suggestion cuts to the core of environmental restoration: Can we restore native species that have disappeared from urban areas like this?

While this may not look like cougar country now, according to accounts by old-timers, bears and cougars were regularly seen in Federal Way as late as the 1950s.

It’s one thing to restore a species to a pristine ecology. It’s quite another to re-establish critters in an area as heavily urbanized as this area. And yet, we have a remarkable recent success with a species that hasn’t been seen on Hylebos Creek for decades: The beaver. Not exactly fearsome bears, but our trees may be quaking in their roots.

I discovered the beavers accidentally one day last October, while making a routine site visit to the Lower Hylebos Marsh. This 13-acre marsh restoration in Fife was built in 2005 by the National Oceanic and Atmospheric Administration (NOAA) and the Friends. The project had created three intertidal marshes whose water level rises and falls with the tide. When we arrived that day, we discovered the water level of the site’s upper marsh was far higher than it had ever been. The cause, we soon discovered, was two recently built dams on the marsh’s inlet and outlet channels. Our marsh had become a beaver pond.

The good news is that beavers are really good critters to have on salmon streams. Their ponds provide important rearing habitat for juvenile salmon. More beavers equals more salmon. Beaver ponds also provide habitat for a range of other species. From a restorationist’s perspective, the arrival of beavers at the site is strong piece of evidence that we got the design right.

The long-toothed rodents are likely immigrants from the nearby Puyallup River. Ecologists tell me that the state’s trapping ban has resulted in a population explosion that likely has younger animals heading out to look for new habitats.

Since the site is a restoration project, we do worry about the beavers eating and harvesting young trees. However, the site is so blessed with trees that it would take a long time, and a lot more beavers, before we saw that level of impact. The most serious concern is the potential to create flooding of nearby landowners. This doesn’t appear to be a threat at the Lower Hylebos site. However, if more beavers arrive in the Hylebos and establish themselves upstream in parts of Federal Way, problems could indeed arise. If that happens, there are a number of “beaver deceiver” devices on the market that can maintain water levels at a safe volume without destroying the beaver dam.

The return of beavers to the Hylebos is a very encouraging sign. It suggests that there is considerable room to restore some native species to our urban streams and wetlands. It won’t be nearly as exciting for human inhabitants as having cougars and bears, but somehow, I’m thinking it’ll be a lot more popular.