Hiking Safety in Guam

Guam's trails range from easy coastal walks to challenging jungle routes requiring river crossings. Knowing what you're getting into before you set off is essential.

• Southern Guam (Talofofo, Inarajan, Merizo) has the most diverse hiking terrain including waterfalls and jungle routes.
• Popular trails: Tarzan Falls (jungle waterfall), Ritidian Point (coastal/limestone), Mt. Lamlam (highest point at 407m).
• Ritidian Wildlife Refuge: requires a free permit from the US Fish & Wildlife Service — plan ahead.
• Flash flooding is a serious risk on all jungle and river trails from May to November.
• Some trails require river crossings — these become extremely dangerous during or after rain.

• Water: minimum 2 liters per person — more for longer hikes or hotter days.
• Footwear: sturdy closed-toe trail shoes or hiking boots. Sandals and flip-flops are not safe for jungle trails.
• Sun protection: SPF 50+ sunscreen, wide-brim hat, and UV-protective clothing.
• First aid kit: bandages, antiseptic, tweezers, blister pads, pain relief.
• Fully charged mobile phone, though signal is often absent in jungle areas.
• Emergency whistle: standard safety gear for any trail — three blasts signals distress.
• Insect repellent (DEET-based) for protection against mosquitoes and other insects in the jungle.
• Snacks/energy food: trail mix, energy bars, or bananas for longer hikes.

Flash floods are the most dangerous hazard on Guam's jungle and river trails. They can occur with little warning, even if there is no rain at your location.

• Never hike on river trails or cross any stream during or immediately after rain.
• Check the weather forecast at weather.gov/guam before every hike — afternoon thunderstorms are common May–November.
• If you hear the sound of water increasing suddenly or see water rising, move immediately to high ground.
• Tarzan Falls trail involves river crossings — do NOT attempt this trail during rain or wet season without a guide.
• Avoid low-lying valley trails during any rain warning or when skies are darkening.
• Start hikes early morning (before 8am) to be well clear of trails before afternoon storm potential.

• Brown tree snake: invasive species, non-venomous, but bites can cause infection. They're nocturnal and rarely encountered during day hikes.
• If bitten by any snake: wash wound thoroughly with soap and water, seek medical attention.
• Coconut crabs: large crustaceans near coastal areas — they won't pursue you but their claws are powerful; give them space.
• Monitor lizards (skinks, geckos): harmless and common on all Guam trails.
• Bees and wasps: disturb no hives or nests; move slowly away if you encounter a swarm.
• Feral pigs: occasionally seen in southern Guam — give them a wide berth; sows with piglets can be aggressive.

• Always tell someone where you are going and your expected return time before setting out.
• Never hike alone in remote jungle areas — go with at least one other person.
• Hire a local guide for unfamiliar, remote, or waterfall trails — they know current conditions.
• Download an offline map (Google Maps or AllTrails) as backup to GPS when signal fails.
• Start early — aim to be back at the trailhead before 2pm to avoid afternoon rain and peak heat.
• Stay on marked trails — cutting through unmarked jungle is dangerous and can damage protected habitat.
• If lost: stay put, activate your emergency whistle, and wait for help rather than wandering further.