Arboretum Safety

Our foremost concern is for your safety while you are in the Arboretum.  Minnesota does not have many outdoor hazards, but there are still some issues to be aware of while you are enjoying the out of doors.

Personal Safety

While Northfield is generally considered to be a safe area, and we have very few reports of Arboretum users being harassed or harmed, we encourage you to always be aware of your surroundings and take precautions to ensure your personal safety. The Arboretum is open to the public and there are no emergency telephones once you get away from the main part of campus. We encourage you to walk/run with a partner and carry a cell phone. Any suspicious activity should be reported to campus security (507-222-4444) or call 911 if an emergency. 



Severe storms/Tornados:  Spring is the most likely time to encounter severe thunderstorms or tornadoes, but they can happen any time of year. We encourage you to sign up for cell phone text messages regarding campus emergencies, available through Campus Security. You should also be aware of the severe weather sirens that will be activated if a tornado is detected nearby. The sirens will emit a 3-5 minute steady blast and repeat the blast if necessary. These sirens are tested the first Wednesday of every month at noon. If you hear the sirens or receive a text message about severe weather you should seek shelter immediately. There is no safe place out of doors during a lightning storm so you are strongly encouraged to seek indoor shelter. If you are outside and hear thunder the only way to significantly reduce your risk of becoming a lightning causality is to get inside a building or a hard-topped vehicle as fast as you can. If you are too far from a building to seek indoor shelter during a thunder storm avoid open areas and stay away from isolated tall trees, towers, or utility poles. If a tornado is spotted, and you cannot get to indoor shelter, you should look for a low area such as a ditch, away from trees if possible. Lay flat in the low area, cover your head with your arms, and wait for the tornado to pass.  Learn more about outdoor weather safety from the National Weather Service.

Severe Cold

Snow covered trees

Typical Minnesota winters can be quite cold and if you plan to spend much time out of doors you should become familiar with clothing options to stay warm and dry. Frostbite and hypothermia are real hazards that can be easily avoided especially if you wear layers that keep you dry and protect your skin from exposure to the cold by wearing the right clothing. Learn more about smart weather dressing and winter sports basics through Recreational Equipment, Inc. and the signs of frostbite or hypothermia.


The old cattle tunnel into the arb flooded after the September rainstorms.

Cannon River Under Normal Conditions

The Cannon River is a great place to canoe, kayak, float or fish. During all of these activities it is highly recommended that you wear water sandals or some sort of footwear to avoid foot injury. In addition to sharp clam shells (we have a type called the “heel splitter” for good reason) it is not uncommon to find rusty tin cans, broken glass and fishing lures. We also recommend that you avoid ingesting the water, and don’t venture in if you have open cuts.

Cannon River Under Flood Conditions

While the Cannon River may seem like a sleepy shallow river most of the time, flood conditions can turn it into a raging torrent. The floods of September 2010 were so extreme that the track and West Gym fields were flooded and most of the bridges in downtown Northfield were closed to traffic. While most floods are not that extreme, the river can become dangerous any time of year if there have been heavy rains.  During floods boating and swimming in the river can be very dangerous and is not advised. The Minnesota Department of Natural Resources maintains information on river conditions

Problem Animals

While southern Minnesota does not have large animals like wolves or bears to be concerned about, we do have small animals that can cause problems.  Most of these can be easily avoided if you know what to watch for. Listed below, in order of size, are animals that might cause you trouble.


tick on hand

The Arboretum is home to two kinds of ticks that are active throughout the warm weather months, April – October. Ticks are small animals that feed on the blood of mammals. Wood ticks (also sometimes called dog ticks), while unpleasant, are not typically considered dangerous. The adult or young may bite you but they do not normally carry disease in our area. Deer ticks (also called the black leg tick), are very small and are known to carry Lyme disease, human anaplasmosis, and babesiosis. You should be aware of the symptoms of these illnesses so you can seek medical attention. See more about both of these types of ticks provided by University of Minnesota Extension. Ticks climb to the top of a stem of grass and wait for a mammal (a dog, mouse, deer, rabbit, or you) to brush up against the grass. They grab on to the passing mammal and then crawl around looking for an easy place to settle in for a meal. The best way to avoid ticks is to stay on the trails and avoid walking through or lying down in grassy areas. Other good strategies include:

  • Wearing long pants
  • Tucking your pant legs into your socks (a classy look)
  • Spraying a repellent that contains pyrethrum on your socks, pants, and shoes
  • Checking yourself and your clothing thoroughly after being out in the Arboretum

Tick transmitted disease take 24 hours or more to be transmitted once they begin to bite you. If you take the time to check yourself after being out in the Arboretum it is likely you will find any ticks before they have bitten you or before any disease transmission has occurred. If you find a tick that has started to bite you, the best way to remove it is to use a pair of tweezers and grab the tick as close to the mouthparts as possible and pull directly out. Carleton Student Health and Counseling can assist you. Don’t let all this talk of small parasitic animals freak you out! Arboretum staff work in the Arboretum every day, we find many ticks and we are alive to tell the tale.  What is the best way to dispose of a tick once you find one? Immobilize the tick with a piece of tape and toss it in the garbage. Or keep it as trophy taped to your dorm room door. Or start a contest with your friends to see who can accumulate the most! Seriously, if you are bitten by a small tick that you believe may be a deer tick, you may want to keep the tick to show your medical personnel.

Wasps and Bees

Wasp by Leng Sok, '10

Wasps and bees may be encountered at any time during the warmer months in the Arb, although they are more common as the summer progresses and into the fall until the first hard frost. Most stinging insects will not bother you if you leave them alone with the exception of ground nesting bees. If you are so unfortunate as to step on a nest of ground nesting bees you should leave the area as quickly as possible. If you are stung the best way to reduce swelling and pain is to ice the sting location. If you know you are allergic and have a prescription for an epi-pen we encourage you to carry it with you when in the Arboretum. If you have never been stung and are unsure about whether you are allergic you should become familiar with what to watch for by consulting with your medical provider or reading more on this topic.

Small Mammals (Mice and Meadow Voles)

Close up of a mouse.

Small mammals are known to carry a respiratory disease called hantavirus. While very uncommon in this area, this is a serious disease and it is good to know how to avoid it. This disease is more likely to be encountered in enclosed areas such as cabins, sheds or other buildings where mice have gathered for shelter or to find food. This is a dangerous disease that has effected hikers who take shelter in old cabins  – not a possibility in the Arb – but could also be experienced in piles of logs or lumber where mice may have gathered. It is best to avoid any area where you find large amounts of mouse droppings.


two Raccoons poking their heads out of a log

Raccoons are not typically noticed in the Arboretum unless they are sick with distemper or rabies. As nocturnal animals, they are hidden in hollow trees or under logs during the day. If you see a raccoon during the day it is likely sick and should be avoided.  Raccoons also carry a roundworm parasite that can be encountered in their feces. Raccoons often have toilet areas where you will see large amounts of their droppings on logs or stumps, especially near the river. You can easily pick up this disease if you accidentally touch the toilet area, so watch where you put your hands and wash with soap and water as soon as possible if you do run into one of these spots.

Problem Plants

While we do not have any carnivorous plants in the Arboretum, there are several problem plants that you will want to learn how to avoid. They are listed below, in order of danger.

Wild Parsnip

This is the WORST! Wild parsnip is a non-native plant that is spreading across Minnesota, including the Northfield area. Exposure to the sap of this plant causes your skin to be super sensitive to the sun. After ten minutes your skin can be sensitized, a condition known as phytophotodermatitis. Skin sensitized in this way will be subject to severe sunburn – almost as if you had been burned on a hot stove. During this time you can avoid burns by staying out of the sun. This sensitivity lasts about 8 hours, so by the next day you can be out in the sun again without fear. The rash or burn will not be apparent for several days, and then become worse until day four or five. The rash remains for about two weeks and then slowly subsides, although discoloration of the skin may be present for a year or more.  

In addition to learning how to identify this plant, you can also:

  • Stay on the trails. Arb staff do their best to keep this plant away from the trail edges.
  • Wear long pants, socks, and closed toe shoes.
  • If you have been exposed to the plant you can go indoors, put on clothes to cover your skin, or put on heavy sunblock. By the next day you will no longer be sensitive. 
Wild Parsnip Flower
Wild PArsnip

For more information, see the Minnesota DNR or the pages about wild parsnip.

Poison Ivy

Most people know that poison ivy has leaves in groups of three, but they might not be able to identify this plant in the many forms that it takes.  Poison ivy can be a small low plant, a vine, or a fairly tall shrub. The oil found on the surface of all parts of this plant is what you want to avoid; you can get the oil on your shoes or pants and then later transfer it to your hands, face, etc. The oil causes a rash that shows up several days after exposure, and can last for 10 days to two weeks. Not everyone is sensitive to this plant, but many people report becoming sensitive to it after years of never having a problem. Arboretum staff remove the plant whenever they find it growing near the trails. The best way to avoid the rash is to know how to identify the plant and avoid touching it or touching it with any of your personal gear. You may encounter poison ivy any time of year since it is a woody plant and the oil is present on the stems even in the winter. Other ways to reduce your risk, if you think you have been exposed, include:

  • Wash with cool water and soap (hot water spreads the oil more)
  • Wash your hands after you put on or take off your shoes
  • Wash your clothes and shoes with cool water (and wash yourself after touching your clothes)
Poison Ivy vine
Poison Ivy

For more information, see the page about poison ivy.

Stinging nettles

Most commonly found in damp areas along the river or stream, and usually in the shade, stinging nettles are unpleasant but only cause discomfort for a short period of time. Stinging nettles come in several types — wood nettle, stinging nettle — both of which have small, sharp hairs on their stems and leaf edges. The hairs contain histamine that causes stinging and localized swelling when the hair brushes your skin. This stinging goes away within 10-15 minutes. Stinging nettles are only encountered during the growing season, typically mid-April through October.

Stinging Nettle
Stinging Nettle
Close up of a Stinging nettle.

For more information, see the pages on stinging nettles and wood nettles.