Riddles Lake
depth
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Depth scale
Survey readout
Riddles Lake is mapped to a depth of 18 ft on the Indiana DNR survey and covers about 78 acres in St. Joseph County, Indiana. Depths come from the Indiana DNR survey of 2019.
Measured from the Indiana DNR lake bathymetry survey.
- Deepest mapped contour
- 18 ft
- Survey year
- 2019
- Surface area
- 78 acres
- Shoreline
- 1.94 mi · irregular
- Aquatic vegetation
- 24% of surface · NDVI estimate
- Public access
- No public DNR launch identified
Additional depth details6 contours
- Contour depths
- 0–18 ft
- Recorded point soundings
- 18 ft
Provenance
Sources: IN DNR Lake Bathymetry, USGS 3DEP, USDA NAIP (public domain), OpenStreetMap (ODbL).
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Map details & sources4 sources
All layers registered to one bounding box; positions in WGS 84.
Survey-derived depth contours drape over USGS 3DEP elevation, with a USDA NAIP aerial basemap and OpenStreetMap shoreline. Color shows surveyed depth; dark lines are the survey's own isobaths.
- Coordinates
- 41.50535, -86.26250
- IN DNR lake ID
- 123166010
- Vertical exaggeration
- 3.0×
- Basemap
- USDA NAIP · public domain
- Model size
- 2.0 MB
Paddling
Paddling Index methodology v1.0 · calculated 2026-09-21Riddles Lake has a mostly natural, lightly developed setting, generally sheltered geometry, nearby higher-volume roads. No special watercraft restriction is identified in the current source.
Why this score?5 components
Included in the index
| Component | Rating | Points of weight | Measurement |
|---|---|---|---|
| Natural setting | Very Good | 22.6 of 35 | 66% natural land cover within 150 m of shore (44% forest, 23% wetland; 10% developed) |
| Geometric wind exposure | Very Good | 22.8 of 29 | mean fetch 698 m · 5% of sampled water within 500 m of shelter · generally short fetch |
| Watercraft controls | None identified | 8.8 of 18 | No special watercraft restriction identified in the current DNR source. Motors permitted, subject to general law. |
| Public access | Not listed | — | No DNR-listed access site. Township, county and road-end launches are not in this source, so this is not evidence that access is poor — the component is excluded and the remaining weights are renormalized. |
| Road isolation | Mixed | 5.6 of 18 | nearby higher-volume roads · 4 INDOT-classified segments within 1.2 km, peak 19,069 vehicles/day |
Additional paddling considerations
These describe the lake but are not part of the v1 Paddling Index and do not change the number above.
- Wake sensitivity
- Low — wide enough that wakes disperse over most of the lake
- Aquatic vegetation
- Moderate — approximately 24% mapped coverage · NAIP aerial imagery (NDVI)
- Observed motorized activity
- Unknown — No lake-level measurement of boat traffic is available. Legal permission to operate motors is not evidence of use.
- Wildlife habitat potential
- Moderate — 44% forest and 23% wetland cover within 150 m of shore
Compare Indiana lakes by Paddling Index →
Fish you might catch
from DNR surveys16 species with recent evidence in this lake — sized relative to each other. Illustrations are AI-generated representative adults in everyday colors, not photographs (provenance).
Common Carp
Gizzard Shad
Hybrid Sunfish
Golden ShinerAbout these fish → the Fish of Indiana guide
Fishing rules for this lake Beta
Size and daily limits for the 16 species found here — 13 open to harvest.
These are hook-and-line size and daily limit rules. The fishing code sets no closed season for these species on inland lakes, but posted property rules can close a water — see the notes. Gear, spearing and bow fishing, netting and bait collection are set by other sections of 312 IAC 9 and are not shown here.
Official rule text for this lake
“An individual may take minnows at any time during the year.” — 312 IAC 9-7-15(a), Indiana Administrative Code
From 312 IAC 9-7 (Sport fishing), Indiana Administrative Code (readopted 2025-03-25), and the 2026-2027 Indiana Fishing Regulations Guide · verified 2026-09-15. Regulations can change — the Indiana Administrative Code (312 IAC 9-7) is the controlling source; verify current regulations before fishing. Official regulations
Fishery
surveyed 2014Gamefish Largemouth Bass 57 · Bowfin 9 · Walleye 7
Panfish Bluegill 194 · Black Crappie 15 · Hybrid Sunfish 13
All survey species16 species
Gamefish
Panfish
Bullhead & catfish
Forage & nongame
Non-native species records
1 recordPlants & algae
How to identify invasive species in Indiana lakes →
What does non-native mean?
USGS records identify non-native species that have been documented for this lake or its shoreline. Non-native does not necessarily mean invasive, and historical records do not confirm current presence.
Source: Midwest Glacial Lakes Partnership Conservation Planner; underlying nonindigenous species records from the USGS Nonindigenous Aquatic Species database.
Riddles Lake — common questions
How deep is Riddles Lake?
The deepest contour on the Indiana DNR bathymetric survey of Riddles Lake is 18 ft. That is the deepest depth the historical survey map records, which may differ from the deepest point of the lake itself.
How big is Riddles Lake?
Riddles Lake covers about 78 acres in St. Joseph County, Indiana.
What fish are in Riddles Lake?
Species with survey, catch or recent-stocking evidence include largemouth bass, walleye, black crappie, bluegill, bowfin, brown bullhead. The page lists all 16 species and the evidence behind each.
Is there public access to Riddles Lake?
No public launch for Riddles Lake is shown in the Indiana DNR's public access data. That is not the same as the lake being private -- municipal and private ramps are not in that source.
