Transcona's Dave McMillan, host pro Dean North, Hecla's Scott Parker and St. Charles assistant Joel Rhodes each posted even-par 71 to share the lead through 18 holes at the 6,520-yard course on Monday.
The 54-hole championship winds up Wednesday.
The results will also likely determine Manitoba's player of the year. Parker and Glendale's Andrew Steep are No. 1-ranked North's closest pursuer in that competition.
After the four even-par 71s on Monday, Pine Ridge's Jason Ludke pulled in just one shot back with a 72. Sharing sixth spot at 73, just two shots away heading for Day 2, are Hecla's Andrew Hunt, Glendale's Steep and Al Scott of Gimli's Links at the Lake.