The 12 Hours of Lawrence Woods returns to Medford, Massachusetts on July 18th, inviting runners to explore the lesser-known trails within Middlesex Fells Reservation's Lawrence Woods for a half-day endurance challenge. This event covers approximately five miles in one continuous loop around the woods and doesn't cross over into other sections; participants can expect minimal aid stations with basic supplies like water and snacks. Participants are advised to arrive early, starting registration at 7:00 AM followed by a pre-race briefing at 7:50 AM. The course opens promptly at 8:00 AM for the start of the event, which runs until 8 PM that evening. Runners should be aware of the limited aid station setup in the woods about a quarter mile from Ramshead Road’s high school parking lot. The Lawrence Woods area has a rich history within Medford's community and is known among locals as an off-the-beaten-path gem for runners seeking solitude or challenging terrain. The event attracts approximately 200 participants annually, who contribute to supporting local environmental initiatives through their participation fees. This year’s edition promises the same level of dedication to both endurance running and preserving natural beauty. The course itself is a continuous loop around Lawrence Woods, featuring hard-packed trails that are generally dry but require runners to be self-sufficient with water, snacks, and other essentials as aid stations will only provide minimal support. The start/finish line along with the single aid station is located in the woods near Ramshead Road’s high school parking lot. Race day weather typically sees temperatures ranging from an average low of 19.7°C to a peak of around 28.5°C, making for comfortable yet warm conditions throughout the event hours. Humidity levels hover at about 74%, with intermittent chances of light rainfall averaging just over three millimeters. Runners should prepare for potential wind speeds averaging eleven kilometers per hour and plan accordingly.
12hrs 12 Hours • Start: 08:00:00 • Fee: $12.00
In this endurance challenge, participants can sign up to run or walk a continuous loop through the woods for twelve hours straight. The registration fee is $12.00, offering access to minimal aid stations along the way but encouraging runners to carry their own supplies due to limited support on course. To register for the 12 Hours of Lawrence Woods, visit [https://ultrasignup.com/register.aspx?did=138218](https://ultrasignup.com/register.aspx?did=138218). Bib pickup and registration take place at Ramshead Road’s high school parking lot from 7:00 AM onwards. Early arrival is recommended to avoid any last-minute rush. Participants should bring identification for bib pickup, as well as a bag containing personal supplies such as water bottles, snacks, and small chairs if they wish to set up their own spot along the course. The start line address is Ramshead Road in Medford, Massachusetts, with an age requirement of 18 years or older for participation. The 12 Hours of Lawrence Woods event in Medford, Massachusetts on July 18th offers a unique opportunity for runners and hikers to experience the lesser-known trails within Middlesex Fells Reservation’s Lawrence Woods. This challenging half-day endurance race provides not only physical exertion but also contributes directly to local conservation efforts through participant fees.
Races Offered
12hrs
Jul 18, 2026
straighten
Distance —
12 Hours
terrain
Type —
Running
timer
08:00
sell
$12.00
Weather History
These values represent the 3-year monthly averages for July in Medford.
thermostatTemperature
19.7° / 28.5°
wb_sunnyFeels like
20.4° / 29.4°
light_mode
Avg sunshine hours
11h 22m
water_drop
Avg rainfall
3.9 mm
ac_unit
Avg snowfall
—
air
Avg wind speed
11.4 km/h (Light breeze)
opacity
Sweat loss rate
High
terrain
Course conditions
Hard and dry surface
sunny
Max UV Index
Very High (8.0)
humidity_mid
Humidity
74.8%
wb_twilight
Sunrise
05:22
nightlight
Sunset
20:17
About Medford
Learn more about the host city, Medford.
Medford is a city in Massachusetts with a population of 60,000 (2020). It is home to Tufts University.
