Supporters of an effort to legalize marijuana say they are planning to start gathering petition signatures in May for a ballot proposal.

Several speakers at this weekend's Hash Bash in Ann Arbor told the crowd, estimated at 10,000, to rest up for the May push.

Organizers want to make marijuana legal for those 21 years old and up, similar to alcohol.

They say the sales tax on marijuana will bring in more money for schools and roads.

The hope is to put a ballot proposal before voters in November 2018.