The land was surveyed in April last year, and council is now negotiating to buy the access strip, council's parks team leader Wendy Bainbridge said.
However the seller is setting conditions, such as the ability to freely exercise horses in the park - which could conflict with mountain bike use.
There are two other barriers to the access. A bridge on the route was closed in the 2018 summer, deemed unsafe after inspection by an engineer. Money was put aside to fix it but the repair has waited until other access issues are settled.
And there has never been a legal level crossing for the railway line between the bridge and the park. An engineer has designed a crossing, which will cost the council $10,000 to $15,000, but KiwiRail has not yet approved it.
"This has been going on for a long time. It would be really nice to get this resolved," committee chairwoman Helen Craig said.