Flat grade share
- Idaho Falls Marathon
- 96.4% Favoured
Idaho Falls Marathon vs Jack & Jill's Downhill Marathon & Half
A data-led head-to-head using sourced race facts and available derived figures under one published methodology.
Data current as ofIdaho Falls Marathon or Jack & Jill's Downhill Marathon & Half — which comes out ahead?
Idaho Falls Marathon and Jack & Jill's Downhill Marathon & Half split the available advantages, so the better choice depends on which metric matters most to the runner.
Route comparison snapshot
Idaho Falls Marathon
- Mapped route
- Held
- Elevation profile
- Held
- course flatness
- 0.3% Favoured
- flat grade share
- 96.4% Favoured
- lower ascent
- 69 m
- climbing density
- 1.6 m/km
- net elevation
- 15 m
- maximum grade
- 10.9%
Jack & Jill's Downhill Marathon & Half
- Mapped route
- Held
- Elevation profile
- Held
- course flatness
- 1.5%
- flat grade share
- 36.1%
- lower ascent
- 783 m
- climbing density
- 18.5 m/km
- net elevation
- -268 m
- maximum grade
- 31.0%
| Metric | Idaho Falls Marathon | Jack & Jill's Downhill Marathon & Half |
|---|---|---|
| Flat grade share | 96.4% ✓ | 36.1% |
| GAP factor (% slower than flat) | 0.3% ✓ | 1.5% |
| Uphill share | 1.8% | 28.4% |
| Steep-up share | 0.1% | 12.1% |
| Downhill share | 1.8% | 35.5% |
| Total ascent (m) | 69 m | 783 m |
| Climbing density (m/km) | 1.6 m/km | 18.5 m/km |
| Longest climb length (m) | 530 m | 540 m |
| Longest climb gain (m) | 9 m | 24 m |
| Longest climb average grade | 1.7% | 4.5% |
| Total descent (m) | 52 m | 1,051 m |
| Net elevation (m) | 15 m | -268 m |
| Max absolute grade | 10.9% | 31.0% |
| Start elevation (m) | 1,416 m | 780 m |
| Finish elevation (m) | 1,431 m | 512 m |
| Scenic score | 83/100 | 100/100 ✓ |
| Conditions | 43/100 | 75/100 ✓ |
GAP factor (% slower than flat)
- Idaho Falls Marathon
- 0.3% Favoured
Uphill share
Steep-up share
Downhill share
Total ascent (m)
Climbing density (m/km)
- Idaho Falls Marathon
- 1.6 m/km
Longest climb length (m)
- Idaho Falls Marathon
- 530 m
Longest climb gain (m)
Longest climb average grade
Total descent (m)
Net elevation (m)
Max absolute grade
- Idaho Falls Marathon
- 10.9%
Start elevation (m)
- Idaho Falls Marathon
- 1,416 m
Finish elevation (m)
- Idaho Falls Marathon
- 1,431 m
Scenic score
- Idaho Falls Marathon
- 83/100
- Jack & Jill's Downhill Marathon & Half
- 100/100 Favoured
Conditions
- Idaho Falls Marathon
- 43/100
- Jack & Jill's Downhill Marathon & Half
- 75/100 Favoured
Only metrics available for at least one side are shown. A ✓ marks the better value for each metric (higher-is-better aware). Scores are out of 100 when available. Ascent, climbing density, max absolute grade and median finish describe course or field context and are not marked as better or worse.
Race facts that change the decision
| Fact | Idaho Falls Marathon | Jack & Jill's Downhill Marathon & Half |
|---|---|---|
| Schedule | Exact race date not confirmed. Event weekend starts 2026-07-25 (legacy event-level date). | Exact race date not confirmed. Event weekend starts 2026-07-25 (legacy event-level date). |
| Location | Idaho Falls, Idaho | Hyak (Snoqualmie Pass) to North Bend, Washington |
| Actual distance | 42.2 km | 42.2 km |
| raceindex.org mapped route held | Held | Held |
| raceindex.org elevation profile held | Held | Held |
| Course type | Loop | Point To Point |
| Surface | Unavailable | Smooth, hard Packed gravel rail trail |
| Elevation character | Gently Rolling | Net Downhill |
| Terrain | Road | Trail, Gravel |
| Scenery | Riverside, Waterfront, Countryside, City, Historic, Parkland | Mountain, Waterfront, Countryside, Historic, Parkland, Forest, Lakeside |
| Atmosphere | Community, Charity | Destination, Scenic Tour, Wilderness |
| Technicality | Non Technical | Non Technical |
| Total ascent | 69 m | 783 m |
| Climbing density | 1.6 m/km | 18.5 m/km |
| Total descent | 52 m | 1,051 m |
| Net elevation | 15 m | -268 m |
| Max absolute grade | 10.9% | 31.0% |
| Flat grade share | 96.4% | 36.1% |
| GAP factor | 0.3% | 1.5% |
| Cutoff | 6:00:00 | 6:30:00 |
| Entry model | Open | Open |
| Qualifying status | Boston_equivalent | Boston_equivalent |
Schedule
- Idaho Falls Marathon
Exact race date not confirmed. Event weekend starts 2026-07-25 (legacy event-level date).
- Jack & Jill's Downhill Marathon & Half
Exact race date not confirmed. Event weekend starts 2026-07-25 (legacy event-level date).
Location
- Idaho Falls Marathon
- Idaho Falls, Idaho
- Jack & Jill's Downhill Marathon & Half
- Hyak (Snoqualmie Pass) to North Bend, Washington
Actual distance
- Idaho Falls Marathon
- 42.2 km
- Jack & Jill's Downhill Marathon & Half
- 42.2 km
raceindex.org mapped route held
- Idaho Falls Marathon
- Held
- Jack & Jill's Downhill Marathon & Half
- Held
raceindex.org elevation profile held
- Idaho Falls Marathon
- Held
- Jack & Jill's Downhill Marathon & Half
- Held
Course type
- Idaho Falls Marathon
- Loop
- Jack & Jill's Downhill Marathon & Half
- Point To Point
Surface
- Idaho Falls Marathon
- Unavailable
- Jack & Jill's Downhill Marathon & Half
- Smooth, hard Packed gravel rail trail
Elevation character
- Idaho Falls Marathon
- Gently Rolling
- Jack & Jill's Downhill Marathon & Half
- Net Downhill
Terrain
- Idaho Falls Marathon
- Road
- Jack & Jill's Downhill Marathon & Half
- Trail, Gravel
Scenery
- Idaho Falls Marathon
- Riverside, Waterfront, Countryside, City, Historic, Parkland
- Jack & Jill's Downhill Marathon & Half
- Mountain, Waterfront, Countryside, Historic, Parkland, Forest, Lakeside
Atmosphere
- Idaho Falls Marathon
- Community, Charity
- Jack & Jill's Downhill Marathon & Half
- Destination, Scenic Tour, Wilderness
Technicality
- Idaho Falls Marathon
- Non Technical
- Jack & Jill's Downhill Marathon & Half
- Non Technical
Total ascent
- Idaho Falls Marathon
- 69 m
- Jack & Jill's Downhill Marathon & Half
- 783 m
Climbing density
- Idaho Falls Marathon
- 1.6 m/km
- Jack & Jill's Downhill Marathon & Half
- 18.5 m/km
Total descent
- Idaho Falls Marathon
- 52 m
- Jack & Jill's Downhill Marathon & Half
- 1,051 m
Net elevation
- Idaho Falls Marathon
- 15 m
- Jack & Jill's Downhill Marathon & Half
- -268 m
Max absolute grade
- Idaho Falls Marathon
- 10.9%
- Jack & Jill's Downhill Marathon & Half
- 31.0%
Flat grade share
- Idaho Falls Marathon
- 96.4%
- Jack & Jill's Downhill Marathon & Half
- 36.1%
GAP factor
- Idaho Falls Marathon
- 0.3%
- Jack & Jill's Downhill Marathon & Half
- 1.5%
Cutoff
- Idaho Falls Marathon
- 6:00:00
- Jack & Jill's Downhill Marathon & Half
- 6:30:00
Entry model
- Idaho Falls Marathon
- Open
- Jack & Jill's Downhill Marathon & Half
- Open
Qualifying status
- Idaho Falls Marathon
- Boston_equivalent
- Jack & Jill's Downhill Marathon & Half
- Boston_equivalent
Facts are shown only when they exist in the sourced race record; Not held means no sourced value is held for that race.
Common questions
Which is flatter, Idaho Falls Marathon or Jack & Jill's Downhill Marathon & Half?
Idaho Falls Marathon has the lower GAP factor, making it the flatter course on our route model and more favourable on gradient alone.