Olson Lake
Location 45 acres
Fishing Outlook
Largemouth Bass
Very Good
A total of 82 Largemouth Bass were collected ranging from 8.1 – 19.7", with 82 of those fish greater than stock size (7.9"). Average length was 13.0". The PSD exceeded its respective target ranges while the PSD-P fell just below its respective ranges. Body condition (as indexed by relative weight) exceeded the 90th percentile. A high body condition indicates sufficient forage for fish growth. Despite Largemouth densities being high, and good Largemouth body condition, very few preferred-sized Largemouth were collected. It’s possible that larger fish are present but were difficult to collect due to the large amount of vegetation in the water during the survey.
Muskellunge
Developing
A total of 2 Muskellunge were collected ranging from 27.8 – 27.8", with 2 of those fish greater than stock size (20.1"). Average length was 27.8". The 2 Muskellunge collected were quality-sized fish. This is to be expected from a newly stocked lake. As the population ages, future analysis will be done to accurately quantify population demographics.
Bluegill
Good
A total of 151 Bluegills were collected ranging from 1.2 – 7.9", with 116 greater than stock size (3.1"). Average length was 4.8". The PSD exceeded its respective target ranges while the PSD-P fell below its respective ranges. Body condition (as indexed by relative weight) exceeded the 90th percentile. A high body condition indicates sufficient forage for fish growth. Despite Bluegill densities being high, and good Bluegill body condition, very few preferred-sized Bluegill were collected. It’s possible that larger fish are present but were difficult to collect due to the large amount of vegetation in the water during the survey.
| 2025 | Channel Catfish | Advanced Fingerling (4 - 7") | 720 |
| 2025 | Muskellunge | Adult | 45 |
| 2024 | Channel Catfish | Advanced Fingerling (4 - 7") | 760 |
| 2024 | Muskellunge | Adult | 49 |
| 2023 | Channel Catfish | Advanced Fingerling (4 - 7") | 760 |
Contact
815-979-1237
Description
Olson Lake is an artificial impoundment in the watershed of Pierce Lake. It was built in order to be a silt basin and prevent Pierce Lake from filling up with sediment. The lake was first filled in 1990, and it was 50 acres in size at the time of filling. The maximum depth was 12.0 feet with an average depth of 6.5 feet. Olson Lake has a tremendous coverage of aquatic vegetation, consisting of curlyleaf pondweed, Eurasian milfoil and white water lily. The lake was constructed using Build Illinois Funds and its main purpose was to provide swimming opportunities. To this end, an extensive beach was constructed on the south shoreline with a bathhouse and parking. Only a canoe or kayak launch facility is found at Olson Lake.Fishery History
Olson Lake has a maximum depth of 12 feet and an average depth of 6.5 feet. The lake is 45 acres in size with a watershed of 6,520 acres (144:1 ratio). The storage capacity is 292.5 acre-feet. The lake's 1.36-mile shoreline, other than the beach, is undeveloped consisting of both woody vegetation and natural grasses. The shallow depth of the lake has led to the development of extensive growth of aquatic vegetation. Seven species of aquatic plants have occurred naturally, and white-water lily was planted in 1990.Site Regulations
Only carry-in boats and electric trolling motors are allowed on Olson Lake.
Site-Specific Fishing Regulations:
- All Fish: 2 pole and line fishing only and each pole must not have more than 2 hooks or lures attached while fishing
- Channel Catfish: 6 Fish Daily Harvest Limit
- Large or Smallmouth Bass: 14 inch Minimum Length Limit; 1 Fish Daily Harvest Limit
- Muskie: 36 inch Minimum Length Limit; 1 Fish Daily Harvest Limit (statewide regulation)
Additional Information
Planning to eat your catch? Fish Consumption Advisory information can be found here: Fish Consumption Advisory PageBath Map
