The road was closed on Saturday afternoon to allow for a 'significant police response' to deal with the situation, Lancashire Police said.
The force said around 150 of the 250 people who made their way to the site following an earlier anti-fracking demonstration tried to breach the secure site where exploration company Cuadrilla wants to drill four wells and test frack for deep-lying gas.
An investigation is underway although there have been no arrests so far.
A demonstration at Maple Farm went ahead 'peacefully' according to organisers who said around 500 people attended. The event ended at 2pm at which point, police said, a large number of people made their way towards the shale gas site.
In a statement issued on Saturday afternoon, Lancashire Police said: "Following an earlier event at Maple Farm badged as a national day of anti fracking action, a significant number of protesters believed to number around 250 made to the Cuadrilla site on Preston New Road.
"Around 150 of those proceeded to try to breach the fencing and to gain access to the site.
"Those engaged in the behaviour are largely thought to be from outside the area and not from the local protest groups.
"A significant policing response was required to prevent disorder while maintaining the right of those who wished to protest lawfully. This was done calmly and professionally by the officers involved."
The protesters' actions were condemned by Cuadrilla chief executive officer Francis Egan, who said: “Organisers of the anti-fracking rally held at Maple Farm, Preston New Road, claimed they wanted a peaceful demonstration. This has been very far from the case.
"We have seen dozens of activists aggressively breaking through fencing to trespass on the local farmer’s land site causing damage to equipment.
"We have also seen distasteful intimidation at the local farmer's home where he lives with his family.
"This is unacceptable, irresponsible behaviour which has resulted in road closure, disruption to the local community and landowner and the need for significant police force resource. The unacceptable face of anti-fracking activism is clear for all to see.”
Local resident, Claire Stephenson, of Preston New Road Action Group, said the initial event at Maple Farm was 'brilliant' and the support from around the country was 'heartening'.
She added: "We had a really lovely event and then a water blessing afterwards.
"Our event ended at 2pm so we can't comment any anything after that. Our message is peaceful protest."
But she said she could understand the frustrations of those who continued on to the fracking site, adding: "The feeling of anger won't go away. You can't really say how people will react."
A Lancashire Police spokesman added: "No arrests have been made at this time, although an investigation will follow to identify any criminality.
"Our approach is always to ensure a consistent and coordinated policing response and ensure a balance between the rights of people to lawfully protest, together with the rights of the wider public, including local businesses, to go about their lawful activities.
"We aim to prevent, where possible, crime and disorder, but where it does occur we will provide an effective, lawful and proportionate response."