Jacob French, 21, of Western Australia is making the trek to raise money for Starlight Children's Foundation, a charity for seriously ill children.

He crossed the South Australian border on Monday afternoon and by Wednesday he had arrived in Nhill.

Mr French left Perth in July last year and hopes to reach Sydney on March 31.

He is pushing a buggy to carry food, water and a swag, while collecting money in a tin along the way.

He said the trek was going well but he was exhausted.

"I only had four hours' sleep on Wednesday night because I had to organise the finer details of the route between Melbourne and Sydney," he said.

"We had a bit of a rearrangement with my schedule on Wednesday because there were lots of people having photos at Nhill.

"I didn't want anyone to miss out so we took the afternoon off so that all the families and children could get a picture."

Mr French said he hoped to walk 40 kilometres yesterday and make it to Horsham by tonight.

He planned to stay with his friend and fellow trooper and Star Wars fanatic Nick Wilson in Horsham last night.

Mr French said he had enjoyed the journey and the response from people along the way.

"I love to make people smile. Half the reason I did this trek was to entertain people and the other part is helping the Starlight Children's Foundation," he said.

"I'd like to say a massive thank you to everyone who has donated.

"We have raised more than $70,000 so far, which has blown what I thought was a pretty high target of $50,000 out of the water.

"There are lots of very generous people out there."

Mr French said people could donate to the cause on his Facebook page Troopertrek 2011.