With less than two months remaining on the primary calendar, it is crunch time for the Republican candidates hoping to force an open convention or, in Donald Trump’s case, lock up the nomination before the party meets in Cleveland this summer.

The final stretch promises to be a manic hunt for delegates and a high-stakes test of campaign strategy, playing out in states that have rarely seen the primary campaign spotlight. And, without any debates on the calendar, the fight will instead be waged in the trenches.

Most of the remaining 854 Republican delegates, a small share of whom are unbound by state votes, will be awarded in 16 primaries in seven contests spread out over the next eight weeks. Roughly one-third of those remaining delegates will come from just two states: New York, which votes next week, and California, which will cast ballots June 7, the final day of voting.

As the map has shrunk, the candidates’ focus has narrowed. Trump last week canceled campaign jaunts to Colorado and California to hone his resources on winning the New York primary, where he could possibly sweep the delegates.

Sen. Ted Cruz did make the trip to the Republican state convention in Colorado on Saturday, where he swept the state’s delegates in a commanding campaign-organization show of force. During an interview Sunday on “Meet The Press,” Trump’s convention manager and lead delegate hunter Paul Manafort accused Cruz’s campaign of “Gestapo tactics, scorched-earth tactics” in wrangling delegates. Cruz’s campaign called the charges “falsehoods” and defended its delegate operation as the mark of a capable campaign.

Manafort did acknowledge that Trump’s campaign has not been hitting on all cylinders. “We weren’t playing in Colorado and they did,” he said, referring to Cruz’s campaign.

With Cruz out West and Trump in New York, Ohio Gov. John Kasich will turn his attention briefly this week to Maryland, with a campaign stop there Wednesday. The state will vote April 26, with 38 delegates at stake. Even that small prize would help Kasich, who has only won his home state and still trails Marco Rubio in the delegate count, although Rubio has been out of the race for nearly a month.

Although it is a medium prize, with 57 delegates at stake, Indiana’s vote next month will likely be an important bellwether for the last stretch of the primary and could lend important momentum to its victor. The state is the sole one to vote May 3, and so the result will receive outsized media coverage and attention from the candidates.

Rex Early, Trump’s campaign chairman in Indiana, last week told the Indianapolis Star that the campaign is getting a late start organizing there. But, he added, “We’re going to catch up.”

The GOP primary will almost certainly reach its climax June 7, with votes in New Jersey, Montana, New Mexico, South Dakota and the race’s crown jewel, California, where candidates are already mining for political gold. Cruz stopped there Monday for events in Irvine and San Diego, two Republican strongholds in a deep-blue Democratic state.

For Cruz and Kasich, the objective on the final day of voting will be to keep Trump short of the 1,237 delegates he would need to lock up the nomination before Cleveland. If the celebrity businessman comes close, but indeed falls short, the party’s 112 unbound delegates could come into play in the five weeks between the end of voting and the start of the convention.

At that time, too, the candidates would amplify their pitches to win the nomination. Indeed, that process is already starting.

“What, are we going to pick someone who can’t win?” Kasich said Sunday on CBS’ “Face the Nation.” “I mean, that would be nuts.”