Fort Union National Monument
Exposed to the wind, within a sweeping valley of short grass prairie, and along the eroded Santa Fe Trail, lie the adobe walled ruins of the largest 19th century military fort in the region.
Hours
See this week's hours below.
- Entrance fee
- The Park Service lists no entrance fee for this site.
- Phone
- 505-425-8025
- Address
- 3115 NM Highway 161, Watrous, NM 87753
About Fort Union
Exposed to the wind, within a sweeping valley of short grass prairie, and along the eroded Santa Fe Trail, lie the adobe walled ruins of the largest 19th century military fort in the region. From 1851 to 1891, Fort Union functioned as an agent of change, desired or not, in the New Mexico Territory and throughout the Southwest.
Hours
Fort Union National Monument Operating Hours
The monument grounds and visitor center are generally open 7 days a week, from 8:00 AM - 4:00 PM. The monument is closed Thanksgiving Day, Christmas Day, New Year's Day.
| Monday | 8:00 AM to 4:00 PM |
|---|---|
| Tuesday | 8:00 AM to 4:00 PM |
| Wednesday | 8:00 AM to 4:00 PM |
| Thursday | 8:00 AM to 4:00 PM |
| Friday | 8:00 AM to 4:00 PM |
| Saturday | 8:00 AM to 4:00 PM |
| Sunday | 8:00 AM to 4:00 PM |
Changes to these hours
- Winter Hours of Operation, Sep 7 to May 27, 2027: 8:00 AM to 4:00 PM
- Thanksgiving Day Holiday Closure, Nov 26: Closed
- Christmas Day Holiday Closure, Dec 25: Closed
- New Year's Day Holiday Closure, Jan 1: Closed
Getting there
Fort Union National Monument is located in the Northeastern portion of the state of New Mexico. 8 miles off of Interstate I-25 on State Highway NM 161. New Mexico: From Albuquerque (156 miles), Santa Fe (94 miles) or Las Vegas, NM (28 miles) take I-25 North, exit 366 at Watrous, 8 miles on NM 161. Colorado: From Denver (313 miles), Colorado Springs (243 miles) or Raton (95 miles) take I-25 South, exit 366 at Watrous, 8 miles on NM 161.
Weather
Fort Union is situated at 6,760 feet above sea level. Daytime temperatures between June and September may exceed 90 degrees Fahrenheit. Winter temperatures often drop below 32 degrees Fahrenheit. Temperatures may vary within 50 degrees in a 24-hour period. During the winter, it is not uncommon for the temperatures to drop below 0°F (-18°C.) During the summer, expect high temperatures, intense sunlight and extremely low humidity.
Things to do
Bookstore and Park Store, Guided Tours, Historic Weapons Demonstration, Junior Ranger Program, Living History, Self-Guided Tours - Walking, Shopping.
Source: National Park Service data feed, checked September 24, 2026. Hours shown are the Park Service's posted standard hours plus any date changes it lists. Official page for Fort Union ↗