Tamarack Ottawa International Marathon

Why this race belongs on a competitive runner's shortlist

World Athletics Elite Label marathon with a certified Boston-qualifying course. The 2026 course crosses between Ottawa and Gatineau, passes Parliament Hill and the Canadian Museum of History, then returns along the Rideau Canal. Suits runners wanting a capital-city race and international field; the middle hills and potential late-May warmth make rigid even-pace expectations unwise. It suits runners wanting a capital-city race and international field. The 2027 event date is confirmed. Detailed route, elevation and operations below are the 2026 reference; they are not confirmed 2027 arrangements.

Course overview

2026 road circuit with western Tunney's Pasture section, an Ottawa to Gatineau loop, Rockcliffe/New Edinburgh excursion and final Rideau Canal out-and-back. The start is Ottawa City Hall and the finish is Rideau Canal beside downtown Ottawa. The route takes in Parliament Hill, Tunney's Pasture, Chaudière Bridge, Gatineau, Alexandra Bridge, Rockcliffe, Rideau Canal, Dow's Lake. Rolling urban and bridge sections in the first 25 km precede a gentler canal-side final section, although small rises remain.

0 to 10 km

The 0 to 10 km interval includes Parliament Hill, Wellington Street, Tunney's Pasture, Kichi Zibi Mikan, Chaudière Bridge. Go&Race's 2026 modeled profile drops 15 m from 1 to 2 km, then shows rolling lower ground and a 9 m net rise from 9 to 10 km. The official map places Chaudière Bridge before the 10 km Gatineau section. Water/XACT stations approximately every 3 km; XACT fruit bars at 8.5 km. Exact drink-station positions are not listed on the current event page. Avoid spending energy banking time on the early descent; the 8.5 km fuel opportunity precedes the bridge/Gatineau section.

10 to 21.1 km

The 10 to 21.1 km interval includes Gatineau, Lac des Fées, Alexandra Bridge, Sussex Drive, Rockcliffe. The modeled 2026 profile shows+11 m net from 15 to 16 km, +10 m from 18 to 19 km and+12 m from 20 to 21 km, with the highest modeled points near 20 to 21 km. Water/XACT approximately every 3 km. Carry carbohydrate for this section if the 8.5 km bar does not fit your plan; the next specifically published fruit-bar station is 22 km. Cap effort across the Alexandra Bridge and Rockcliffe rises instead of trying to recover every lost second immediately.

21.1 to 32 km

The 21.1 to 32 km interval includes New Edinburgh, Sussex Drive, Colonel By Drive, Rideau Canal, Dow's Lake. Go&Race models a 16 m net descent from 22 to 23 km, then smaller undulations, including+8 m from 31 to 32 km. Water/XACT approximately every 3 km; fruit bars at 22 km. The next fruit-bar point 32.5 km falls just beyond this interval. Let the descent back from New Edinburgh reduce effort, take fuel at 22 km, and move onto the canal with enough reserve for the remaining distance.

32 to 42.195 km

The 32 to 42.195 km interval includes Colonel By Drive, Rideau Canal, Dow's Lake, Queen Elizabeth Drive, Ottawa City Hall area. Modeled profile remains roughly 63 to 72 m through 32 to 42 km, with a 7 m net rise 35 to 36 km and 8 m net descent 36 to 37 km; it is gently undulating rather than perfectly level. Fruit bars at 32.5 km, with water/XACT approximately every 3 km and toilets at each water point. If effort and conditions allow, press progressively on the return canal section; avoid fighting exposed stretches or rising heat just to match a fixed split.

Elevation checkpoints and how to read them

Total ascent is 201 m. Named route-analysis fallback: FindMyMarathon publishes 201 m ascent/199 m descent, course updated 12 May 2026. This is a modeled 2026 profile, not an organizer-published or confirmed 2027 total. Go&Race provides independent modeled per-kilometer evidence and has a different minimum 48 m; do not combine its segment figures into a claimed reconciliation of FindMyMarathon's total. Middle-course climbing across Gatineau/Alexandra Bridge and Rockcliffe, notably 15 to 16, 18 to 19 and 20 to 21 km; descent 22 to 23 km; smaller canal-side rises remain late.

Aid stations and race-day logistics

Drink-station spacing is approximate. Approximately every 3 km: Water and XACT hydration; portable toilets. 8.5, 22 and 32.5 km: XACT fruit bars. The start is Ottawa City Hall, 110 Laurier Avenue West. Organizer recommends OC Transpo buses/O-Train and its Travel Planner to Ottawa City Hall because road closures and parking constraints affect access. No guaranteed 2027 special service or station-specific route was verified. The 27 km checkpoint at Pretoria Bridge must be reached by 11:30 am; marathon completion expected within 7 hours. 2026 reference: Lisgar Field directly behind Festival Plaza; use tear-off bib tag on a closed bag, retrieve with bib after leaving Recovery. Published 2026 Sunday hours 6 am to 1 pm;2027 hours not verified. The published baggage hours end before the seven-hour race limit; confirm collection arrangements in the final guide.

Practical pacing plan

Avoid spending energy banking time on the early descent; the 8.5 km fuel opportunity precedes the bridge/Gatineau section. Cap effort across the Alexandra Bridge and Rockcliffe rises instead of trying to recover every lost second immediately. Let the descent back from New Edinburgh reduce effort, take fuel at 22 km, and move onto the canal with enough reserve for the remaining distance. If effort and conditions allow, press progressively on the return canal section; avoid fighting exposed stretches or rising heat just to match a fixed split. Push only while effort and form remain controlled. Adjust pace for wind, rain and temperature on race day; the monthly historical sample is not a race-morning forecast.

Historical weather pattern

May history for Ottawa, Canada gives a typical daily temperature range of 35.5 to 81.7 degrees Fahrenheit, daily maximum sustained winds of 6.2 to 14.1 mph, and at least 1 mm of rain on 39.7 percent of days. Historical conditions can change, so check the race-week forecast before travel and again on race morning.

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