CONCORD, N.H. — More all-terrain vehicle riders are being seen on New Hampshire trails — and now, on some local and state roads — and the Fish and Game Department’s 42 conservation officers are feeling a bit stretched.

For many years, it was illegal for the vehicles to be on the roads, but that’s changed in recent years. Towns in Coos, Grafton, Sullivan counties and elsewhere have been allowed to open up their road systems to the off-road recreational vehicles, beyond the state’s 1,200 miles of riding trails.

Riding is allowed on state roads in communities such as Gorham and Berlin. Police are in charge of handling reckless driving and speed complaints. But conservation officers, who enforce regulations primarily on trails, also have responded to the roads as they juggle with non ATV-related issues like searches and rescues, hunting and wildlife issues.

“We’ll help wherever we can, but we can’t possibly take on all the additional road enforcement that goes along with the expansion of these road networks,” said Maj. John Wimsatt, the department’s assistant chief of law enforcement.

Wimsatt said the department, which oversees ATV registrations and safety classes, is also getting calls from families regarding utility-terrain vehicles — which seat up to six people — asking about helmets, seat belts, and child car seats, questions they’re not used to tackling.

Off-road vehicle registration is on the rise. A decade ago, there were over 26,000 residents and non-residents registered in the state for ATVs, UTVs and trail bikes. That number dipped when the recession hit and was down about 5,000 by 2012. Registrations now is over 30,600 for the fiscal year ending June 30, the highest number so far.

They include an increase in 10-day temporary registrations, reflecting participants in an annual summer ATV festival at the Jericho Mountain State Park in Berlin. The park also just hosted a Polaris Camp RZR event by the recreational vehicle manufacturer, drawing thousands of riders. Conservation officers assisted at both events.

A state commission was formed this year to make recommendations to the Legislature to address jurisdictional responsibilities and safety for ATVs. Members include representatives of the Fish and Game and other departments, law enforcement groups, off-road recreational vehicles and municipal associations and more.