Be an environmental Watchdog

CSERC focuses our efforts on the northern Yosemite region, a spectacular expanse of the Central Sierra Nevada, but we cannot be everywhere all the time. As a watchdog, you help us see which areas need our attention.

We want you to join our efforts by helping CSERC identify environmental issues, whether it is resource damages or invasive or rare species, so we can investigate and follow up as needed. Help protect the environment while you are enjoying it by being an environmental watchdog.



Be a Watchdog

How to be a watchdog

Keep an eye out for resource damage in our region, as well as invasive species and rare species.
Be observant, take note of where you are and take photos. When photographing resource damage, think about providing context, perspective and visual cues to more accurately capture the impacts. Especially for rare wildlife, photos are extremely helpful to verify your sighting.

Here are things to watch out for:

Look for resource damage

Grazing Damage

Streambank and Meadow Damage

Wet areas are especially sensitive to disturbance. Look for freshly exposed dirt, crumbling streambanks, and deep holes or "pocks." Livestock as well as illegal OHV use can cause serious damage to meadows and wet areas. Read more about the importance of healthy meadows to wildlife here.


Keep an eye out for illegally created user trails causing damage. Trails crossing water or heading straight up steep hills can create erosion and watershed problems. Legal trails often have signs indicating the types of intended use and don't usually cause significant resource damage. More information about erosion threatening our water can be found here.

Erosion on an OHV Trail

Documenting poor fence conditions

Poor Fence Condition

Sensitive wet areas and meadows are sometimes protected by fences to prevent livestock from grazing there. Unfortunately, many of these fences are poorly maintained, if at all.

CSERC partners with the Forest Service where possible to help with fence maintenance. If you see a fence in disrepair that looks like it would be ineffective in keeping cattle out, let us know so we can follow up! Read about previous efforts to help prevent grazing violations due to poor fence conditions.

Watch out for invasive and noxious weeds

Invasive plants are usually non-native, and threaten not only our native plants but also the insects, birds and others that evolved with those native plants. There are native lookalikes for many, so know before you pull.
It’s best to take photos, note your location and confirm with us or Forest Service staff if you aren't sure! You will often find dense patches of them; due to their "invasive" nature, they tend to take over.
Here are some common weeds and their native look alikes:

Bull Thistle (non-native)

Bull Thistle

Anderson Thistle

anderson thistle

Quick and easy bull thistle removal

Yellow Star Thistle (non-native)

Yellow star thistle

Often found along roadsides and other disturbed areas with abundant sun, these similar plants cover vast areas that become nearly impassable due to the sharp spines covering the plant.

Tocalote (non-native)


Wooly Mullein (non-native)


Look for its large, hairy leaves in a rosette. It sends up a tall flowering stalk with many yellow flowers. While its flowers may be beautiful, its leaves acidify the soil and make it extremely difficult for other plants to grow.


Yellow Hawkweed (native)

Yellow hawkweed

Many yellow daisy-like flowers are native to the area. Look (don't feel!) for thorns to help confirm non-native thistles. Native flowers tend to be much "friendlier" and lack the sharp defenses that help invasives establish themselves.


Keep an eye out for rare and elusive wildlife

A few wildlife species in the Sierra Nevada have small or declining populations. Identifying where the remaining individuals persist is necessary to protect them. Here are some tips to help you identify rare species should you be so lucky as to see one! Learn more about the remote camera stations CSERC maintains in both Yosemite National Park and the Stanislaus National Forest in our efforts to capture photographs of these rare species.

Pacific Fisher

Fisher prefer mature, closed-canopy forests and are very elusive. They are larger and darker than similar species, and have been described as having the face of a weasel and the tail of a fox.

Pacific Fisher

Pacific Fisher - Photo John Jacobson / NPS

American Marten

Marten are found at higher elevations than Pacific Fisher and are smaller and lighter in color than their relatives. They favor Red Fir and Mountain Hemlock forests with abundant downed wood. Marten are tree-dwellers but are also known to hunt in high elevation boulder fields.


River Otter

River Otter


American Mink

These two more abundant species are most likely to be confused with Pacific Fisher and/or American Marten. River otter are found very near water. Mink travel farther from water but are much smaller than both Fisher and River Otter.



Porcupine - Photo by Peggy Sells


The abundance of porcupine is unknown, but many suspect their numbers have dramatically declined. Their once large numbers diminished as they were hunted and poisoned to prevent the damage they can cause to young conifers in plantations. CSERC has been requesting porcupine sightings since 2011 to gain a better understanding of how many are left.



Wolverine - Photo Peggy Sells

Wolverine require deep snow and large territories and are distinguished from their relative the Badger by their solitary nature, much larger size, and distinctive lighter stripe reaching from their shoulder to their tail.


Badgers are smaller and lighter than Wolverine. They have a light stripe that runs from their nose to their tail down the center of their back.

Successes 2014 Badger

Sierra Nevada Red Fox

Sierra Nevada red fox. Photo from the CA Department of Fish and Game.

Photo from the CA Dept of Fish & Game.

Look for dark shins, black behind the ears and a white tipped tail to identify Sierra Nevada Red Fox. They are most likely to be seen in sub alpine and alpine environments. Read more about our local SNRF discovery

Gray Fox

There are two species of common fox that can be confused with Sierra Nevada Red Fox. Despite their name, Gray Fox can appear quite red, but will always have silvery gray coloration too. The non-native Red Fox is similar to Sierra Nevada Red Fox, but is slightly larger and lighter, and is found at lower elevations.

Gray Fox Pups

Report your findings to us