FIND
YOUR WILD.
A little mud. A big adventure.
Two trail races. One unforgettable forest.
YOUR TRAIL. YOUR CHALLENGE.
BUILT FOR ADVENTURE.
Good trails.
Better company.
Leave the pavement behind. Run through the towering trees, singletrack, and logging roads of McDonald Forest. Chase a fast finish or soak up the adventure—there’s a place for you at the Mac.
EVERY STRIDE GIVES BACK ↗5K
Your first trail race. Your next personal challenge. A shorter distance with a full dose of forest.
15K
More miles. More climbing. More of the Mac. Take the long way through an Oregon trail-running gem.
Know your way
through the Mac.
Explore the 5K and 15K courses. Open a full-size map or save a PDF for race day.
A taste of the trails.
Follow the bright green route through the forest.
Go a little deeper.
First loop: magenta. Second loop: bright blue.
Your miles.
Their next
opportunity.
Race proceeds support local high school cross-country athletes and teams and the Oregon Running Foundation’s work to move young lives forward through running.
Opportunities. Inspiration. Shoes. A stronger running community starts here.
MEET THE MAC COMMUNITY ↗Know before
you go.
Registration opens
November 26, 2026
- Race date
- Saturday, March 6, 2027
- Distance
- 15K & 5K
- Start times
- 15K — 9:00 a.m.
5K — 9:30 a.m. - Location
- OSU McDonald Forest
Corvallis, Oregon - Entry fees
- 15K — $40 / 5K — $30Youth 18 & under receive 50% off the registration fee.Registration fees increase by $5 after January 15, 2027.
When is the next race?
The next Mac Forest Trail Runs will be Saturday, March 6, 2027. Visit UltraSignup for registration, current entry fees, and event details ↗.
Where does the adventure start?
Find us at Peavy Arboretum in Oregon State University’s McDonald Forest near Corvallis. Enter from Arboretum Rd. Stay to the left and Follow Race Parking Signs. View Peavy Arboretum on the map ↗
What are the trails like?
Expect singletrack and logging roads, hills, and the possibility of mud. View the 5K and 15K course maps to explore your route. Courses may change due to weather, trail conditions, or forest management activities.
Where can I find past results?
Relive your race or find your next target. Browse the results archive ↗
Can I help without racing?
Volunteers and sponsors help make the Mac possible. Email the race director to ask about volunteering or sponsorship. We’d love to have you involved.
The forest is calling.
March 6, 2027 · 5K & 15K
Choose your distance and register on UltraSignup.
March 14, 2026
5k & 15k
**Alert ** Due to unexpected scheduling conflicts, and to further support the Corvallis Trail Series, we have a new date for the Mac Forest Trail Runs
New Date - March 14th, 2026
Lace up your shoes, we are back in action on March 14th, 2026
Join us for the 29th running of the Mac Forest Trail Runs. Beautiful trails and logging roads will take you through the majestic McDonald Forest.
Given the time of year, we can’t guarantee much, but this much we do know, there is a high probability it’s going to be wet; you’ll likely finish with some mud on your shoes and a smile on your face. So basically, it’s going to be a fun adventure in one of the gems of the northwest. Whether an experienced trail runner or a first-timer, we believe you will enjoy every minute of the race. Just a warning, this early season race has a tendency to lead to additional race registrations and future trail races. You have been warned!
Proceeds from the races will benefit local high school cross-country athletes and teams and, further, the mission of the Oregon Running Foundation (“ORF”) to help move the lives of youth forward through the power of running. By providing opportunities, inspiration, and shoes, ORF strives to help youth turn their potential into fulfillment.
What you need to know:
Registration opens November 26th, 2025
Race Date: Saturday, March 14th, 2026
Distance: 15k & 5K
Start Time: 15k @ 9:00am, 5k @ 9:30am
Location: OSU McDonald Forest, Corvallis, Oregon
Cost: 15k - $40, 5k - $30
*Youth 18 & under get 50% off registration fee
** Registration fee increases by $5 after January 15th
Registration: Register at UltraSignup
Course
Single track trails and logging roads in Oregon State University’s McDonald Forest. This challenging course has 1450 ft. of elevation gain (for the 15k) with scenic views on a sunny day, otherwise plenty of mud! Two Aid Stations are located at Cronemiller Lake and the Cap House. Please be advised that, due to weather affecting the trails, the course could change on race day.
Click here for a combined 5k/5k Course Map.
Getting to the Race
Directions to Peavy Arboretum (the race start and finish):
From Portland/Salem and other points north
Take I5 South to Salem Parkway
Make your way to Highway 22 West (Beaches)
Take Highway 22 west from Salem 10 miles to 99W
Turn left (South) on 99W and go 18.8 miles through Monmouth; continue on 99W to Arboretum Road
Turn right, go 0.8 miles and follow the signs, turning right into Peavy Arboretum
From Corvallis
Go North on 3rd Street, which turns into 99W
Go 6 miles north on 99W, turn left on Arboretum Road
Go 0.8 miles and follow the signs turning left into Peavy Arboretum