Colorado Parks and Wildlife (CPW) is giving away about $9,000 in cash and prizes during a fishing tournament that begins next week.
The Elkhead Reservoir Fishing Classic gets underway on Saturday, June 24, at 6:30 in the morning.
The tournament runs through July 2.
CPW is asking anglers to catch the northern pike and smallmouth bass. One fish from each of the species is going to be tagged.
The person who snags the tagged fish will each get a $1,500 cash prize.
Fishers who catch the most pike and bass during the nine-day event will each get $750.
There will also be a number of smaller prizes handed out each day - worth about $4,500.
If no one catches the tagged fish, officials will raffle the remainder of the prize money.
CPW says catching northern pike and smallmouth bass will help the reservoir habitat.
"Those two species have been identified as not compatible with native fish recovery efforts. We are working to replace those fish with other species that are acceptable and compatible with native fish recovery," said Lori Martin, the senior aquatic biologist for CPW's northwest region.
They will be replaced with black crappie, bluegill, and largemouth bass fish.
The contest is free, but competitors do need to pay the $7 daily park entry fee or $18 nightly camping fees.
They must also have a state fishing license.
Click here, for more information on buying a license.