Stored 91 V6 Trooper, started, clutch stuck?

I have a 91 V6 Trooper, stored in garage for a couple of years, awaiting a new exhaust system promised by idiot who ripped off existing one. Finally got paid, went to start it and take it to shop, put clutch pedal down and transmission in reverse, and turned the key.

Wham! Vehicle went scooting out of the garage WITH THE CLUTCH PEDAL DOWN! Jammed on the brake and shut the engine off. Tried it again... and this time nothing. Put clutch in, engine start and vehicle did not move. Put into gear, let clutch out, and vehicle did not move. Checked range to make sure that I had it in 2wd, and did. Vehicle still would not go into gear.

I'm assuming that something bad has happened to the clutch. I've heard of clutches seizing up before, and have even stored a few tractors with a stick holding the clutch pedal in. Have not yet gotten down and looked at it with someone pushing pedal and gears, since I was alone when this happened.

I'd appreciate it if anyone had any bright ideas before I went to have it towed in to the shop. THis is our "camp" vehicle, relegated to mostly backwoods and trailer-hauling use, so of course it's up in the boonies.