Ron Plain of the Aamjiwnaang (AWN'-ja-nong) First Nation says donations such as blankets and food and other offers of help are coming in from within the province and from as far away as California as word spreads through social media.
The protesters are denouncing the Harper government’s omnibus Bill C-45, which they claim eliminates treaty and aboriginal rights set out in the Constitution
Plain says organizers have yet to decide whether to challenge a court injunction granting police the power to end the protest.
Sarnia police have said they won't move to stop the blockade unless there is a safety risk.
Demonstrators say the blockade will continue until Prime Minister Stephen Harper meets with Attiwapiskat Chief Theresa Spence. The leader of the northern Ontario First Nation is on a hunger strike in Ottawa to bring attention to aboriginal issues.
Meanwhile, members of two First Nations near Sault Ste. Marie in northern Ontario have posted a message on Facebook saying they plan to launch their own rail blockade on Thursday to back Spence.
Plain says there is an "air of excitement" at the Sarnia blockade, with Aamjiwnaang youth — who started the protest Friday as part of the national Idle No More movement — building snowmen along the tracks.
"The resolve of the community seems to be deepening," Plain said, adding the demonstration is "turning into a community event as opposed to a blockade."
The protest has seen dozens huddle around tents, tables and vehicles, shutting off rail access to several chemical plants.
"We've got people coming in from all over Ontario. We've got people coming in from the United States to sit in," Plain added.
Plain said a representative for the rail company spoke with organizers Monday, but the talks were not fruitful.
He said the First Nation is unwavering in its stance that the tracks were not laid legitimately.
"Our view is a very solid view in that the tracks are not permitted on that road. There was never any kind of permit issued for those tracks to cross there."
Spence started her hunger strike on Dec. 11, and has been living in a teepee on an island in the Ottawa River that many aboriginals consider to be sacred land.
She is seeking a meeting with Harper, the governor general and First Nations leaders to discuss the treaty relationship.