FAIRBANKS — One of the best days of Joe Dinkins’ 73 years alive is when he won the Nenana Ice Classic 10 years ago.

“I got a lot of gifts that day,” the Fairbanks barber shop owner said. “I got flowers. I got bigger tips that day.”

Some states have a lottery. In Interior Alaska, it’s the Ice Classic, the annual guessing game of when the Tanana River ice goes out. The spring tradition is celebrating its 100-year anniversary this year.

Dinkins won $33,812.50 — he still remembers the sum — which he spent last year when he built a new house. He split the $270,500 jackpot with seven other winners.

“I was happy as a bug in a rug,” he said. “I never won nothing big other than that.”

The guessing started in 1916 when surveyors for the Alaska Railroad bet each other when the ice would go out. Thousands of people have shared in the annual jackpots, which began at $800 and now soar above $300,000.

The contest is open to anyone and costs $2.50 per guess until April 5. Typically, 275,000 to 290,000 guesses are reportedly made.

Patricia Thurman of North Pole has played every year since the late 1980s. She buys her tickets in a pool with two former colleagues at the Fairbanks North Star Borough School District even though the trio is long retired.

“We do it for fun,” Thurman said.

Thurman doesn’t consider herself the gambling type, she said. She might play some pull-tabs once in awhile. Her guessing technique is to base her guesses on birthdays and anniversaries in her family.

“I just try to scramble these numbers up until they make sense,” she said.

In 2007, she shared the $303,272 jackpot, winning about $3,300 after dividing it among 21 other winning tickets and then dividing it with the others in her pool.

She remembers how excited she was the day she won — so excited that she provided her library card number to the Ice Classic organizers instead of her social security number, she said. She called her parents and her sisters with the good news.

Thurman said she doesn’t remember what she did with the winnings.

“I’m sure I saved it,” she said.