OUTPROFIT – Why should a fisherman work when there are so many opportunities to angle for dollars? Among them:

• Mack Days, March 15-May 19 at Flathead Lake, with up to $150,000 in cash and prizes.

The buzz: A top contributor toward the derby’s goal of curbing invasive mackinaw in the lake is Michael Benson of Lonepine, who’s reeled in more than 10,000 fish in a decade of Mack Days derbies.

Benson’s brother, Steven Benson of Four Lakes is no slouch at lake-trouting, having turned in more than 500 fish during this spring’s event alone.

Contestants remove about 50,000 lake trout from Flathead during the spring and fall derbies organized by the Confederated Salish and Kootenai Tribes – and biologists say even more needs to be done to control the big mack population.

Info: mackdays.com.

• K&K Spring Derby, April 20-May 5 at Lake Pend Oreille, with a $15,000 payout including $2,500 for the top rainbow.

The buzz: The club is raising money to reintroduce pure-strain Gerrard rainbows to the lake.

Info: (509) 209-3608; email, rmilliken2004 @yahoo.com.

• Pikeminnow Rewards, May 1-Sept. 30 on the Snake and Columbia rivers, paying $4-8 for each fish caught and turned in to check stations, plus tagged fish worth up to $500.

The buzz: Some sport fishing anglers are making a living off this fishery, with several earning more than $60,000 each during the five-month season.

Info: pikeminnow.org.

• Lake Trout Reward on Lake Pend Oreille continues to offer a $15 bounty for each head of a mackinaw turned into collection stations.

The buzz: Macks are getting harder to catch as numbers are curtailed.

Info: (208) 769-1414.

Bike Swap nets $20K for trail

OUTSTANDING – The second-annual Spokane Bike Swap, held April 13-15 at Spokane County Fair and Expo Center, raised $20,000 for the Friends of the Centennial Trail, said Loreen McFaul, the group’s executive director. That’s more than double the amount raised last year.

The swap attracted more than 2,000 people and 600 used bikes were registered to sell, not to mention the wares of 40 vendors.

Learn how floods scoured scablands

OUTFLOOD – “Anatomy of Cheney- Palouse Scabland Tract,” a free lecture by geologist Gene Kiver, will be presented by the Ice Age Floods Institute, 7 p.m., on Friday at the JFK Library Auditorium, Eastern Washington University, Cheney campus.

• Sign-up for Saturday’s Ice Age Floods annual field trip, which involves a bus tour from Lake Steptoe Ridge to the headwaters of Rock Creek. Cost: $55-$70.

Info: Melanie Bell, (509) 954-4242.

Jet boat races set on St. Joe River

OUTBLAST – The first annual Race the Joe jet boat event is set for May 17-19 based out of St. Maries, Idaho.

Info: href=”http://www.facebook.com/racethejoe”>facebook.com /racethejoe