HalfRuns
Spring - Mud Mountain Dam Marathon & Half Marathon

Spring - Mud Mountain Dam Marathon & Half Marathon

The Mud Mountain Dam Half Marathon offers a fast, paved downhill course through scenic farmland and forest.

Race Date

May 30, 2026

Location

Enumclaw, WA

Standout70

Quick facts

Date
Saturday, May 30, 2026
Location
Enumclaw, Washington
Distance
Half marathon (13.1 mi) + 26.2 Miles
Course
Point to Point
Terrain
Road
USATF certified
Yes
Finishers on record
526

Highlights

Good For

PR Friendly

Course

Fast FlatShaded

The Experience

The Mud Mountain Dam Half Marathon, first run in 2022 and now in its third year, draws runners from around five states for a fast, paved journey. With a typical field of around 200 finishers, this event is growing in popularity, though repeat runners make up about 19% of participants.

The course begins in the scenic town of South Prairie, following the paved Foothills Rail Trail. Runners will experience a gradual downhill route alongside the Carbon River, winding through picturesque farmland and forested areas. The race concludes in front of the historic McMillin Bridge, boasting a net elevation loss of 339 feet, making it a prime candidate for personal bests.

Race-provided description

May 30, 2026 – The Full Marathon Returns! We’re excited to announce that the Full Marathon is coming back on May 30, 2026, and will also be part of our September event. Start planning now for your next Boston Qualifier on this beautiful, fully paved downhill course, no tunnel, no dirt, no BQ penalty.  There’s no excuse not to do the dam thing! Marathon The marathon course begins at Mud Mountain Dam (elevation 1,400′). Runners will follow a fully paved route through picturesque farmlands and forested areas, tracing the path of the Carbon River. The race finishes in front of the historic McMillin Bridge (elevation 200′), with a total net elevation loss of approximately 1,200′. Half Marathon The Half Marathon begins in the scenic town of South Prairie (elevation 467′) and follows a gradual downhill route along the paved Foothills Rail Trail. Runners will enjoy a picturesque journey through farmland and forest, winding alongside the Carbon River and finishing in front of the historic McMillin Bridge (elevation 128′). The course features a net elevation loss of 339 feet.

Logistics

Race Day

Saturday, May 30, 2026

Start Time

8:15 AM

Giveaway

Tech T-Shirt

Start Location

30525 SE Mud Mountain Rd, Enumclaw, WA, 98022

Directions

Course Info

USATF Certified

Course Type

Point to Point

Terrain

road

Scenery

Forest, Rural

Surface

Paved

Difficulty

Ultra-Flat

Net Drop/km

+4.41 m

Separation

51.1%

Also Offers

26.2 Miles

USATF Certified Course

WA23029RMB · Mud Mountain Half Marathon

Net downhill course — fast finishing times are common. Point-to-point course layout.

Quality Score

Standout70
Methodology
Heritage6/20

3 years running

Size11/15

~184 finishers a year

Momentum5/5

growing or steady

Loyalty19/20

19% returning runners

Course & details13/15

USATF certified · 5 timing sources · 8 photos

National draw4/10

runners from 5 states

Front-pack speed3/5

winner 1:22:54

Weather8/10

typical high 64°F

Race Day Weather

5-year historical avg

Start (Low)

45°

Afternoon (High)

64°

Pleasant conditions — light layers at start, comfortable by finish

0.1"

Precipitation

7 mph

Wind

76%

Humidity

Historical Finish Times

How 526 finishers actually crossed the line across 3 years.

Most recent

2024

Total finishers

526

Median time

2:00:12

Latest turnout

212

States

12

10%
25%
75%
90%
1:00p50 median ≈ 2:004:25

Turnout by year

20222024

'22'23'24
See full results

Hover the histogram to inspect specific finish times.

Race Photos

Frequently asked

When is the Spring - Mud Mountain Dam Marathon & Half Marathon?

The Spring - Mud Mountain Dam Marathon & Half Marathon is held on Saturday, May 30, 2026, starting at 8:15 AM.

Where does the Spring - Mud Mountain Dam Marathon & Half Marathon take place?

It takes place in Enumclaw, Washington.

What distances does the Spring - Mud Mountain Dam Marathon & Half Marathon offer?

The half marathon (13.1 miles), plus 26.2 Miles.

Is the Spring - Mud Mountain Dam Marathon & Half Marathon course flat and good for a PR?

The Spring - Mud Mountain Dam Marathon & Half Marathon is a ultra-flat, point to point course. The course is USATF-certified, so finish times can be used for qualifying.

How many people run the Spring - Mud Mountain Dam Marathon & Half Marathon?

HalfRuns has finish records for 526 runners who have completed the Spring - Mud Mountain Dam Marathon & Half Marathon.

HalfRuns editorial — independent, no paid placement.

Explore More Journeys

Can't make it to Enumclaw? Discover other experiences that match your running style.

Search All Races