Passenger and freight train operators were scrambling to find alternatives Wednesday after a massive rock slide blocked a portion of British Columbia's Sea to Sky Highway and a parallel railway system.

Early estimates suggest a key section of the vital transportation artery located about 20 kilometres south of Squamish will be closed for at least 24 hours.

CN, which uses the Sea to Sky railway to transport freight from Vancouver to Prince George and back, is looking a rerouting freight through Kamloops and Boston Bar, said spokeswoman Kelli Svendsen. She said CN officials are in talks with the B.C. Ministry of Transportation.

We are assessing the situation,'' she said.

Meanwhile Rocky Mountain Vacations has rented a plane to transport some passengers who scheduled to travel to Whistler via its rail service, Wednesday.

Chief operating officer James Terry said the company had considered renting a boat, but was prevented from doing so because Wednesday is fireworks night in Vancouver and all available boats are already rented.

Roughly 200 passengers per day travel between Whistler and Vancouver via the Rocky Mountain service.