There are relatively few Maine road races whose popularity obliges them to impose a cap on their number of entrants, but the Patriot 5K in Gray is now among those good-problem-to-have events.

In its four years, the race has grown as fast as its loop course around Crystal Lake, from 256 finishers in 2010, to 405 the next year, to 701 in 2012 and then 776 last year. For the fifth running, on Saturday, May 17, there is an announced limit of 1,000 registrants for “Maine’s fastest and richest 5K,” as the race bills itself, with prizes and cash exceeding $5,000. And there is also a $1,000 bonus for setting a Maine record at the distance.

Put that cherry on top of the Patriot’s generous prize structure – $500 to the male and female winners, plus a $250 bonus for setting a course record – and the total potential individual winnings of $1,750 represents a notably useful sum for a small-town race. Leading the impressive sponsor roster is the Liberty Family Foundation, which is putting up the $1,000 bonuses.

What chance is there that the Maine records could be broken in Gray? A woman needs to outrun former Olympic marathoner Cathy O’Brien of New Hampshire, who raced 16 minutes, 6.18 seconds at the Eliot Festival Days 5K in September 1996. Ten years later, Yarmouth native Pat Tarpy – who qualified for the 2012 Olympic marathon trials by running a 1:03:27 half marathon in 2009 – set what remains the Maine men’s record, also at Eliot: 14:15:72.

You don’t see those numbers every decade in Maine. But the Patriot 5K’s co-directors, Tim Anketell and Michael Smith, point out that not only do you never know who might show up from out of state, there are also Maine contenders not far off the record mark. Exhibit A is Erica Jesseman of Scarborough, who won last year’s race in a blazing course-record 16:20.

Jesseman, 25, is an elite Mainer across the distances. She was the state’s top woman (2:42:32) at Boston on Monday, and her six marathons include a pair of victories at Hartford, where she ran 2:38:13 last fall.

Iliotibial band syndrome materialized after Jesseman’s triumph in Hartford and she missed weeks of training, resuming only in midwinter. Nevertheless, she is characteristically game to give the Patriot 5K a go.

“I really like the race, and I want to see what it has in store for me,” she said Thursday. “After Boston, I’m spending at least a week doing nothing – I don’t want to get hurt again – but I think I’m in better shape this year, and I’m looking forward to getting into the faster stuff.”

Jesseman’s approach to shorter stuff is simple: “5Ks, I just attack,” she said, often alongside fast friends Sheri Piers and Kristin Barry, plus the fast guys. That would probably mean a 5:05-5:10 first mile in Gray.

That first mile is probably the race’s most challenging, rolling and curving and winding and dipping along the west side of the lake.

“It’s got undulations, but you’ve always got that lake view on the right,” points out longtime Gray resident Sam Pfeifle, whose best time in three finishes is 22:38, and who was joined last year by wife, Kristen, and daughter Abby, 9, in her first 5K.

“And then when you get to about the 2-mile mark after turning onto Route 26, the whole last mile is a straight (slightly downhill) shot … The cool thing is, you can kick it in and make up time at the end.”

Among those who would agree is state Rep. Louie Luchini, an Ellsworth Democrat and an 11-time All-America runner at Stanford who won the Patriot 5K in a course-record 14:38 in 2011 and was second (15:04) in 2012.

“It’s a pretty fast course that rolls a bit for the first mile and a half or so, but on the long stretch that follows you can really open up your stride and push the pace pretty hard,” Luchini said. “But to hit that 14:15 (record) time, you need a good field.”

Luchini hasn’t raced since winning the MDI Marathon (2:32:55) in October, after which heavy-duty Legislature duty and horrible winter weather kept him too often sidelined. He may still run the Patriot 5K, but added “that (a record time) isn’t on my radar, though.”

Nor does two-time defending champion Moninda Marube of Auburn, off a 14:52 last year, have designs on a fast time. A hip flexor injury has bedeviled him “winter-long,” and at the New Bedford Half last month he had to drop out at Mile 4. But Marube said Thursday that he plans to put in a couple weeks of training and “at least come to the Patriot, to gauge my fitness. And I like to see the people there, who are so nice.”

The course, and the record?

“If you ask me, it is breakable, it is achievable, but only if we have sacrificial lambs. Someone to take you out to a sub-4:40 first mile, and someone else to (help) pound the second mile the same, where everyone gets tired – it’s the second mile that kills everyone,” Marube said.

“And then the last mile, I gnashed my teeth on the last one, but it’s going downhill; it was the (fastest) mile, and the end is just around the corner. It’s possible to break the record, if people want to take it on. It would be a great, interesting race, and I would like to see it.”

As he may, depending on who shows.

To register and to check out the course map, see www.patriot5K.org. Sign up by Monday to get a T-shirt and a goody bag. The fee is $18 preregistered, $20 day of race.

Note that there’s a kids fun run, too, which is free with medallions for all and begins at 8 a.m.

John Rolfe of Portland is a staff writer and a road runner. He can be contacted at 791-6429 or at:

jrolfe@mainetoday.com