The Continental Divide Trail: A Complete Guide to Hiking the CDT

The Continental Divide Trail is the wildest and least-finished of America’s Triple Crown thru-hikes — roughly 3,100 miles from the Mexican border in New Mexico to the Canadian border in Glacier National Park, following the Rocky Mountains’ spine through five states. Where the AT and PCT are largely continuous, well-marked footpaths, the CDT is still, in places, a route more than a trail. Here’s what to actually know before you commit to it.

📚 Part of the Ultralight Backpacking Gear Guide.

Quick Stats

Why the CDT Is Different

The AT and PCT are both essentially complete, continuous, well-blazed footpaths. The CDT is not fully finished — meaningful sections still rely on cross-country navigation, unmarked route-finding, or alternate roads and trails while the official corridor is completed. This is the single biggest thing that separates the CDT from the other two Triple Crown trails: you need real navigation skill, not just the ability to follow blazes.

Combined with high average elevation (much of Colorado’s segment sits above 11,000-12,000 feet), long stretches between resupply towns, and genuinely remote terrain with limited cell service, the CDT demands more self-sufficiency than the AT or PCT. It’s not a beginner’s first thru-hike.

Best Season to Hike

Northbound (NOBO), starting late April–early May is the standard approach: begin at the New Mexico border, cross Colorado’s high country in July when snow has mostly cleared the passes, and finish in Glacier National Park by September before serious snow returns to northern Montana.

Southbound (SOBO) hikers start in Glacier in early-mid summer (once the park’s snow clears, often not until July) and finish in New Mexico in fall. SOBO avoids New Mexico’s brutal early-season water scarcity but compresses the Glacier/Montana weather window at the start.

The core challenge either direction: timing Colorado’s high passes and Glacier’s snow window correctly. Both are genuinely dangerous to cross under heavy snow, and both clear on their own schedule that doesn’t always cooperate with a hiker’s plan.

Permits

Unlike a single unified permit system, the CDT requires permits only for specific sections:

• Glacier National Park — backcountry permits required, and competitive to secure in peak season. Apply early and have a backup plan.
• Yellowstone National Park — backcountry permits required for the CDT’s route through the park.
• Most of the rest of the trail crosses national forest and BLM land with no permit required.

Start Glacier and Yellowstone permit research months ahead — these are the two genuine bottlenecks in an otherwise permit-light trail.

Resupply Strategy

CDT resupply towns are more spread out and less hiker-optimized than on the AT or PCT — fewer towns cater specifically to thru-hikers, and some resupply stretches run 100+ miles between reliable options. Mail-drop boxes to yourself (general delivery at small-town post offices) are more commonly used on the CDT than on the AT, where buying as you go is more standard. Plan resupply logistics further in advance than you would for the other two trails, and carry a few extra days of food buffer as insurance against town access delays.

Gear Considerations Specific to the CDT

• Navigation is non-negotiable. A GPS app with offline CDT-specific maps (Guthook/FarOut, Gaia GPS) is essential, not optional — parts of the route have no visible tread at all. See our How to Read a Topo Map & Compass guide as a backup skill; don’t rely on electronics alone.
• Bear canister or Ursack required or strongly recommended through grizzly country (Glacier, Yellowstone, much of Montana/Wyoming) — see our Best Bear Canisters guide.
• A satellite communicator is a serious consideration, not a luxury, given the CDT’s remoteness and limited cell coverage. See our Best Satellite Communicators roundup.
• Water carrying capacity matters more in New Mexico’s early stretches — some sections require carrying several liters between sources. See How Much Water to Carry.
• Layering for genuine alpine exposure — afternoon thunderstorms above treeline in Colorado are a real, sometimes fatal hazard. See our Complete Layering System and check lightning safety awareness before big alpine days.

Iconic Sections

• The San Juan Mountains, Colorado — arguably the most spectacular and demanding stretch of the entire trail, high alpine terrain with some of the CDT’s most serious snow and weather exposure.
• The Wind River Range, Wyoming — jagged granite peaks and alpine lakes; see our own Wind River Range Cirque of Towers trip report for a taste of this range.
• Glacier National Park, Montana — the trail’s dramatic finish (or start, SOBO), through grizzly country and some of the most photogenic terrain in the Lower 48. See our Glacier National Park guide.
• Yellowstone National Park, Wyoming — geothermal terrain and serious wildlife density along the route. See our Yellowstone guide.

Who It’s For

The CDT is best attempted by hikers who already have a long-distance trail (or at minimum, extensive multi-day backcountry experience) under their belt, are comfortable with real off-trail navigation, and are drawn specifically to the CDT’s wildness and solitude rather than the more social, established trail culture of the AT or PCT. If this is your first thru-hike, seriously consider the AT or PCT first.

Getting Started

Before committing to a CDT thru-hike:

1. Build real backcountry experience first — multiple multi-day trips with navigation practice, ideally including some off-trail travel.
2. Dial in your gear — see our Backpacking Gear Checklist and How to Pack a 10-Pound Base Weight for the foundation.
3. Train specifically for sustained high-elevation effort — see How to Train for a Multi-Day Hike.
4. Budget realistically — a 5-6 month thru-hike is a major financial commitment beyond just gear; see Ultralight Backpacking on a Budget for the gear side of that equation.

Bottom Line

The CDT is the wildest, least-finished, and most demanding of the Triple Crown trails — real navigation skill, high-elevation fitness, and comfort with remote self-sufficiency matter more here than on the AT or PCT. It rewards that demand with some of the most spectacular, least-crowded high country in the Lower 48.

Related Guides

• 📚 Ultralight Backpacking Gear Guide — the complete guide
• The Pacific Crest Trail: A Complete Guide
• The Appalachian Trail: A Complete Guide
• Glacier National Park: Hidden Gems
• Yellowstone National Park: Hidden Gems
• How to Read a Topo Map & Compass
• Best Satellite Communicators

Carry less. Hike farther.