LOW FUEL,

DEN to FMN is a crapshoot. The loads are generally pretty high, and there is often a weight restriction. Add to that several NRs that travel regularly.
If you go to the Great Lakes website and input the city pair, you can get a general idea of the load based on what fares are available. If there are any "Non Refundable" (cheap) tickets still available, then the load is pretty light.
Otherwise, give GL a call, and they will give you the loads, including the number of NRs that are listed. (Obviously you won't be able to figure the NR number from the website.)
Great Lakes Airlines
The res number is 800-554-5111. To list, they want you to call 5112 during business hours. This is the NR number. Leave a message, they are very good about calling back.
Be sure to list.

Cheers,
Hog